美国总统乔·拜登(Joe Biden)周四宣布向乌克兰提供额外的8亿美元军事援助，并禁止所有与俄罗斯有关联的船只进入美国港口俄罗斯军队发射一场期待已久的大规模夺取国家东部的战役。

拜登在白宫罗斯福厅说:“我们现在正处于一个关键的时间窗口，他们将为这场战争的下一阶段奠定基础。”他补充说，美国和盟国将继续向乌克兰提供“他们需要的设备-他们的部队需要的设备-以保卫他们的国家。”

拜登说，新的援助计划将包括“重型火炮武器、数十门榴弹炮和144，000发榴弹炮弹药”，以及战术无人机。

它遵循另一个相似大小的美国官员本周早些时候告诉ABC新闻，拜登上周宣布了这项计划，但更侧重于火炮和弹药。

埃文·伍奇/美联社

乔·拜登总统在罗斯福酒店就俄罗斯入侵乌克兰发表讲话..

拜登说，美国已经派出“响应乌克兰需求并为支持顿巴斯地区激烈战斗而定制的设备，这是一场不同于其他地方的战争，因为两者的地形都不同-它是平坦的，不是在山区-它需要不同类型的武器才能更有效。”

“每个美国纳税人，我们武装部队的每个成员都可以感到自豪的是，我们国家的慷慨——以及我们军队的技能和服务——帮助武装和击退了俄罗斯在乌克兰的侵略，击退了普京试图夺取乌克兰首都和消灭乌克兰政府的野蛮行径，”拜登补充说。

五角大楼在详细说明该一揽子计划的能力时表示，另外72门榴弹炮和将它们拖上战场的车辆将被送往乌克兰，这反映了榴弹炮在顿巴斯战斗中的重要性，那里的地形开阔开阔。

根据五角大楼的说法，加上上周宣布的18门榴弹炮，运往乌克兰的总共90门榴弹炮“提供了足够装备五个营的火炮系统”。

随着战斗的进行，有人担心美国制造的火炮会进入该地区，这也反映在这是新援助计划的主要部分。

随着这一最新的一揽子计划，美国自2月底开始实施以来，已经宣布了超过30亿美元的军事援助。特别是，这是美国从五角大楼现有库存中提供的第八批援助，使用所谓的总统拨款权来加快交付。

自战争开始以来，已有500多万人逃离乌克兰，拜登还宣布了一项名为“团结乌克兰”的新计划，以快速跟踪来到美国的乌克兰难民。

拜登说:“这项新的人道主义假释计划将补充乌克兰人现有的法律途径，包括移民签证和难民处理程序”，“为乌克兰人从欧洲合法移民到美国提供一个便捷的渠道，这些乌克兰人有美国的赞助，如家庭或非政府组织”。

政府表示，从4月25日开始，美国的个人和实体可以向国土安全部申请资助乌克兰公民。根据政府官员的说法，申请资助乌克兰人的人将被要求申报他们的经济支持并通过背景调查，一个人或实体可以资助多少乌克兰人没有限制。

拜登补充说:“这项计划将会很快，会很精简，并将确保美国履行其承诺，向乌克兰人民伸出援手，而不需要通过我们的南部边境。”

随着他继续向普京施加压力，拜登表示，美国还将禁止所有与俄罗斯有关联的船只进入其港口。

“这意味着，任何船只，任何悬挂俄罗斯国旗的船只，任何由俄罗斯利益集团拥有或运营的船只，都不得停靠美国港口或进入我们的海岸。没有，”他说。

拜登在发表讲话前会见了乌克兰总理丹尼斯·施米哈尔(Denys Shmyhal)，他再次呼吁国会为武器和弹药提供更多资金，因为现有资金“几乎耗尽”，他说，即使财政部周四宣布向乌克兰政府提供额外的5亿美元经济援助，也不包括最新的8亿美元军事一揽子计划。

俄罗斯星期三再次发出最后通牒，允许乌克兰士兵离开马里乌波尔的一家钢铁厂，但是这些士兵几天来一直拒绝投降。经过数周的围困和轰炸，最终夺取了这个战略港口城市，这将有助于俄罗斯军队在克里米亚和东部省份顿巴斯之间建立一座陆桥，克里米亚自2014年以来一直被俄罗斯占领，俄罗斯领导的分裂分子自2014年以来也一直在顿巴斯与乌克兰政府作战。

一名国防官员告诉美国广播公司新闻，顿巴斯预计将成为俄罗斯现在的焦点，但美国仍然担心俄罗斯军队会把乌克兰西部用于向该国运送西方军事援助的道路作为目标。

这名官员补充说，虽然他们还没有这样做，但切断这些供应路线将有助于克里姆林宫孤立东部的乌克兰军队。

一名国防官员告诉美国广播公司新闻(ABC News)，美国认为俄罗斯人将把乌克兰西部用于运送西方军事援助的道路作为目标，以孤立东部的乌克兰军队。

“目前，我们从与乌克兰人的讨论中得知，他们正在获取这些材料，”一名国防部官员周二表示。“它正落入他们的战士手中。”

美国和其他西方国家现在已经向乌克兰提供了近7万件反坦克武器，包括几种肩射导弹。美国和其他国家向乌克兰运送的肩射防空导弹数量接近3万枚。

乌克兰军队使用这些导弹取得了很好的效果，但随着战斗从乌克兰的主要城市和郊区转移到更平坦的东部省份，基辅的军队将需要更多的火炮和弹药。

4架飞机运送8亿美元的军事援助拜登宣布撤军计划一名高级国防官员周三表示，上周在过去24小时内抵达乌克兰，其中一些人携带了美国榴弹炮和155毫米弹药，并补充说，更多设备将在未来24小时内抵达。

美国广播公司新闻问这位官员，为什么美国决定向乌克兰人派遣美国炮兵。

这位官员回应说，“由于地形，以及我们认为他们将与俄罗斯军队对抗的情况，我们很清楚炮兵在他们现在和未来几天的战斗中的重要性。”。据该官员称，另一个原因是“乌克兰人知道如何使用它们不需要繁重的培训”，以及快速运输它们的能力。

在拜登上周首次将俄罗斯在乌克兰的行动称为“种族灭绝”之后，美国国务卿安东尼·布林肯(Antony Johnson)周三警告说，在布加勒斯特目睹的同样的恐怖——“死亡、破坏和暴行”——可能会在乌克兰东部城市马里乌波尔“某个时候”发生，尽管俄罗斯军队似乎已经准备好完全占领这座战略城市。

“我们只能预计，当这股潮水在某个时候也从马里乌波尔退去时，我们将会看到更糟糕的情况——如果可以想象的话，”布林肯说。“因此，由于俄罗斯的侵略，那里的条件和局势确实非常可怕。”

Biden announces new $800M aid package to Ukraine as Russia presses offensive

President Joe Biden on Thursday announced an additional $800 million package in military assistance to Ukraine -- as well as a ban on all Russian-affiliated ships from U.S. ports -- asRussian forces launcha long-expected, large-scale campaign to seize the country's east.

"We're in a critical window now of time where -- they're going to set the stage for the next phase of this war," Biden said from the White House Roosevelt Room, adding the U.S. and allies will continue to provide Ukraine with "equipment they need -- their forces need -- to defend their nation."

Biden said the new aid package will include "heavy artillery weapons, dozens of howitzers, and 144,000 rounds of ammunition to go with those howitzers," as well as tactical drones.

It followsanother of similar size, which Biden announced last week, but focuses more on artillery and ammunition, U.S. officials told ABC News earlier this week.

Biden said the U.S. has sent "equipment that is responsive to Ukraine's needs and tailored to support the intensified fighting in the Donbas region, which is a different war than in other places because both topographically, it's different -- it's flat, it's not in the mountains -- and it requires different kinds of weapons to be more effective."

"Every American taxpayer, every member of our armed forces can be proud of the fact that our country's generosity -- and the skill and service of our military -- helped arm and repel Russia's aggression in Ukraine to beat back Putin's savagery that tried to seize Ukraine's capital and wipe out Ukraine's government," Biden added.

Detailing capabilities in the package, the Pentagon said 72 more howitzers and the vehicles to tow them onto the battlefield are being sent to Ukraine, reflecting the importance of howitzer artillery in fighting in the Donbas, where the terrain is wide and open.

When combined with the 18 howitzers announced last week, the 90 howitzers in total headed to Ukraine “provides enough artillery systems to equip five battalions," according to the Pentagon.

As the fighting progresses, there are concerns about getting American-made artillery into the region, also reflected in that this is the bulk of the new aid package.

With this latest package, the U.S. has announced more than $3 billion in military aid since the start started in late February. In particular, this is the eighth tranche of U.S. assistance from the Pentagon's existing stockpile, using what's known as presidential drawdown authority to expedite delivery.

As more than 5 million have fled Ukraine since the war began, Biden also announced a new program dubbed "Unite for Ukraine" to fast-track Ukrainian refugees coming to the U.S.

"This new humanitarian parole program will complement the existing legal pathways available to Ukrainians, including immigrant visas and refugees processing" and "provide an expedient channel for secure legal migration from Europe to the United States for Ukrainians, who have a U.S. sponsor such as a family or an NGO," Biden said.

Beginning April 25, the administration says U.S.-based individuals and entities can apply to the Department of Homeland Security to sponsor Ukrainian citizens. Those who apply to sponsor Ukrainians will be required to declare their financial support and pass a background check, according to administration officials, and there is no limit on how many Ukrainians a person or entity can sponsor.

"This program will be fast, it will be streamlined, and will ensure the United States honors its commitment to go to the people of Ukraine and need not go through our southern border," Biden added.

As he continues to ramp up pressure on Putin, Biden said the U.S. will also ban all Russian-affiliated ships from its ports.

"That means no ship, no ship that sails on the Russian flag or that is owned or operated by Russian interest would be allowed to dock on the united States port or access our shores. None," he said.

After meeting with Ukraine's Prime Minister Denys Shmyhal ahead of his remarks, Biden again called on Congress to provide more funding for weapons and ammunition because existing money is "almost exhausted," he said, even with an additional $500 million in economic aid to Ukraine's government the Treasury Department also announced Thursday, separate from the latest $800 million military package.

Russia offered another ultimatum Wednesday to allow Ukrainian fighters to leave a steel plant in Mariupol -- but those fighters, for days, have refused to surrender. Finally seizing the strategic port city after weeks of besiegement and bombardment would help give Russian forces a land bridge between Crimea, which Russia has occupied since 2014, and the eastern provinces known as the Donbas, where Russian-led separatists have battled the Ukrainian government since 2014, too.

The Donbas is expected to be Russia's focus now, but the U.S. remains concerned that Russian forces will target the paths in western Ukraine being used to ship Western military aid into the country, a defense official told ABC News.

While they have not done so yet, cutting off those supply routes will help the Kremlin isolate Ukrainian forces in the east, the official added.

The U.S. believes Russians will target the paths in western Ukraine being used to ship in Western military aid in order to isolate Ukrainian forces in the east, a defense official told ABC News.

"Right now, we know from our discussions with the Ukrainians that they are getting this material," a defense official said Tuesday. "It's getting into the hands of their fighters."

The U.S. and other Western countries have now provided Ukraine with close to 70,000 anti-tank weapons, including several varieties of shoulder-fired missiles. The number of shoulder-fired anti-aircraft missiles that the U.S. and other countries have sent to Ukraine is nearing 30,000.

Those missiles have been used by Ukrainian forces to great effect, but as the battle shifts from Ukraine's major cities and suburbs to the more flat eastern provinces, Kyiv's troops will need more artillery and ammunition instead.

Four flights carrying military aid from the $800 milliondrawdown package Biden announcedlast week arrived in Ukraine over the last 24 hours, some of them carrying U.S. howitzers and 155mm ammunition for them, a senior defense official said Wednesday, adding more equipment will arrive over the next 24 hours.

ABC News asked the official why the U.S. decided to send U.S. artillery to the Ukrainians.

"We're mindful of the importance of artillery in the fight that they're in right now and in the fighting in the days to come because of the terrain, and because of what we think they're going to be up against with Russian forces," the official responded. Another reason was "the fact that it wouldn't require an onerous amount of training for the Ukrainians to know how to use them" and the ability to ship them quickly, according to the official.

After Biden called Russia's actions in Ukraine "genocide" for the first time last week, Secretary of State Antony Blinken warned Wednesday that the same horrors witnessed in Bucha -- "death, destruction, atrocities" -- may take place in the eastern city of Mariupol "at some point," even as Russian forces seem already poised to fully capture the strategic city.

"We can only anticipate that when this tide also at some point recedes from Mariupol, we're going to see far worse -- if that's possible to imagine," Blinken said. "So the conditions there, the situation there as a result of this Russian aggression are truly horrific."