角大楼一直在提供俄罗斯入侵乌克兰和乌克兰抵抗努力的每日更新。

以下是一名美国高级国防官员周四在第22天告诉记者的要点:

美国(United States的缩写)嗡嗡声前往乌克兰有效对抗俄罗斯车辆和火炮

在白宫周三宣布100架“战术无人机系统”将成为对乌克兰8亿美元新武器包的一部分后，一名美国官员向美国广播公司新闻证实，这些将是小型“弹簧刀”无人机。

与远程捕食者无人机不同，它看起来类似于小型飞机，并向目标发射导弹，弹簧刀无人机是导弹利用全球定位系统引导自己直接进入目标，引爆有效载荷。

最小的版本，弹簧刀300，适合背包，重量只有5.5磅，射程约为6英里。它可以从一个小迫击炮发射升空，当它离开发射器时，它的翅膀会伸展到位。根据制造商的说法，更大的弹簧刀600重量是9倍多，但携带反装甲弹头，可以打击25英里外的目标。

这两种型号都有一个“起飞”功能，如果平民出现在目标附近或敌人离开该地区，人类操作员可以中止攻击。

这名美国官员无法证实美国将向乌克兰发送哪些版本，但一名美国高级国防官员周四告诉记者，这些版本将对各种目标有效。

“这些战术无人机可以用来对付俄罗斯的车辆和火炮，”这位美国高级国防官员说。

随着俄罗斯军队加大对主要城市的轰炸力度，摧毁俄罗斯远程火炮对乌克兰尤为重要。

基辅7天没有俄罗斯人的进展

这位美国高级国防官员说，离基辅最近的俄罗斯军队仍在市中心西北约9英里处。这与他们上周五估计的距离相同。

这名官员说，他们无法推进，因为乌克兰军队“非常积极地抵抗俄罗斯人的任何行动”，但他补充说，俄罗斯在“远程火力”——导弹和火炮——方面保持优势。

虽然那些最近的部队已经停滞不前，但其他部队正从后面加入他们，并带来了远程火炮。

“所以，看起来他们继续想要包围基辅，这就是你想要使用大炮的原因，”这名官员说。“我们还没有看到这种现象本身，我们只是看到他们将它们转移到适当的位置。”

自周三以来，俄罗斯军队唯一值得注意的进展是在哈尔科夫的东南部，五角大楼评估说，他们已经控制了伊祖姆。该官员表示，他们的意图可能是向南推进到顿涅茨克和马里乌波尔，以封锁顿巴斯地区，防止东部的乌克兰军队向西移动，以保卫其他地区。

敖德萨附近的俄罗斯军舰

这位官员说，美国继续看到俄罗斯海军在黑海北部“离敖德萨不远”的地方活动。这包括大约六艘水面舰艇:至少两艘两栖登陆舰、护卫舰和一艘水雷舰。尽管有这些活动，仍然没有迹象表明即将发生两栖攻击。

这位官员说，与周三不同，没有俄罗斯船只炮击敖德萨周围城镇的迹象。

俄罗斯继续轰炸城市，更多的平民被击中

据该官员称，俄罗斯现已向乌克兰发射了1000多枚导弹。这高于周三估计的980人。这些估计计算了导弹发射，不一定是有效打击。这位官员说，他们无法估计这些弹药最终有多少是哑弹。

这位官员再次表示，俄罗斯人更加依赖“哑”弹药，即非制导武器。

这位官员说，目前还不清楚原因，但表示这可能是为了保存他们的精确武器，或者是他们的精确武器越来越少的迹象。无论如何，这些不太容易辨别的武器被视为对平民的更大威胁。

“我们已经看到对民用基础设施和民用目标的袭击有所增加，”这位官员说，但无法量化损失或伤亡。

乌克兰的s-300

这名官员不愿直接回答美国是否会帮助乌克兰获得俄制S-300远程地对空导弹系统的问题。

Anastasia Vlasova/Getty Images

一名乌克兰军人站在被火箭碎片击中的居民楼旁...

“我们正在与盟友和伙伴合作，继续在短程和战术系统以及远程系统方面向乌克兰人提供安全援助，包括远程防空。这涉及到很多方面，一些国家可以获得比我们的一些系统更适合乌克兰人的库存，因为他们接受过培训，他们操作这些系统，他们了解这些系统，他们对这些系统很熟悉。这是一整套的东西。我已经不再给单个系统命名了，我认为如果我继续这样做会更好。但我们正与各国就所有这些能力进行积极对话，看看他们能做些什么来继续向乌克兰提供支持，”这名官员说。

俄罗斯的假情报运动

“在俄罗斯，有趣的是，我们看到他们的叙述更有影响力。但话说回来，他们关闭了独立媒体。大多数俄罗斯人现在唯一能获得的是国家媒体，所以你可以预期这些故事会被更广泛地消费，甚至被更广泛地相信。但是在俄罗斯之外，几乎没有证据表明他们的信息行动是有效的。事实上，我们看到的恰恰相反，”这位官员说。

俄罗斯士气低落

据这位官员说，美国有轶事证据表明一些俄罗斯部队士气低落。

“我们认为，其中一些原因是领导不力，部队对自己的任务和目标缺乏了解，我认为，由于遭到如此激烈的抵抗，人们的幻想破灭了，”这名官员说。

这位官员还表示，值得注意的是，俄罗斯人在入侵仅三周后就考虑增派部队和物资。五角大楼认为这是由于糟糕的后勤规划和比预期更强的阻力。

US 'Switchblade' drones heading to Ukraine can target Russian vehicles and artillery: Pentagon official

The Pentagon has been providing daily updates on the Russian invasion of Ukraine and Ukraine's efforts to resist.

Here are highlights of what a senior U.S. defense official told reporters Thursday on Day 22:

U.S.dronesheading to Ukraine effective against Russian vehicles and artillery

After the White House on Wednesday announced 100 "tactical unmanned aerial systems" would be part of a new $800 million weapon package for Ukraine, a U.S. official confirmed to ABC News these would be small "Switchblade" drones.

Unlike long-range Predator drones, which look similar to small planes and fire missiles at targets, Switchblade dronesarethe missiles, using GPS to guide themselves straight into their targets to detonate their payloads.

The smallest version, the Switchblade 300, fits in a backpack, weighs only 5.5 pounds, and has a range of about six miles. It can be sent into flight from a small mortar tube, its wings extending into place as it exits the launcher. The larger Switchblade 600 weighs nine times more, but carries an anti-armor warhead and can hit targets up to 25 miles away, according to the manufacturer.

Both models have a "wave-off" feature so that human operators can abort an attack if civilians appear near the target or if the enemy leaves the area.

The U.S. official could not confirm which versions the U.S. is sending to Ukraine, but a senior U.S. defense official told reporters on Thursday that they would be effective against various targets.

"These tactical UAVs can be useful against Russian vehicles and artillery," the senior U.S. defense official said.

Taking out Russian long-range artillery is especially important for Ukraine as Russian forces ramp up their bombardment of major cities.

No Russian progress on Kyiv in 7 days

The Russian forces nearest Kyiv are still about nine miles to the northwest of the city's center, the senior U.S. defense official said. This is the same distance away they were estimated to be last Friday.

They haven't been able to advance because Ukrainian forces "are very actively resisting any movement by the Russians," the official said, but adding that Russia maintains an advantage with "long-range fires" -- missiles and artillery.

Although those nearest troops have stalled, other forces are coming to join them from behind, bringing with them long-range artillery pieces.

"So, it appears that they continue to want to conduct a siege of Kyiv, that's what you want to use artillery for," the official said. "We haven't seen that manifest itself, we're just seeing them move them into place."

The only notable advancement of Russian forces since Wednesday is to the southeast of Kharkiv, where the Pentagon assesses they have taken control of Izyum. The official said their intent is likely to push south toward Donetsk and Mariupol to seal off the Donbas area and prevent Ukrainian troops in the east from moving westward to defend other areas.

Russian warships near Odessa

The U.S. continues to see Russian naval activity "not far from Odessa" in the northern Black Sea, the official said. This includes about six surface-war vessels: at least two amphibious landing ships, frigates, and one mine-warfare ship. Despite this activity, there are still no indications of an imminent amphibious assault.

Unlike on Wednesday, there have been no signs of Russian ships shelling towns around Odessa, the official said.

Russian bombardment of cities continues, more civilians hit

Russia has now launched more than 1,000 missiles against Ukraine, according to the official. This is up from an estimate of 980 on Wednesday. These estimates count missile launches, not necessarily effective hits. The official said they could not offer an estimate of how many of these munitions end up being duds.

Again the official said Russians are relying more on "dumb" munitions, meaning unguided weapons.

The official said it's not clear why, but said it could be an effort to conserve their precision weapons, or a sign they're running low on them. At any rate, these less-discriminate weapons are seen as a greater threat to civilians.

"We have seen an increase of strikes on civilian infrastructure and civilian targets," the official said, but could not quantify the damage or casualties.

S-300s for Ukraine

The official would not directly address questions about whether the U.S. would help facilitate Russian-made S-300 long-range surface-to-air missile systems for Ukraine.

"We are working with allies and partners to continue to provide security assistance to the Ukrainians on short-range and tactical systems as well as long-range systems, to include long-range air defense. And there's a lot that goes into that, and some countries just have access to inventory that are more suitable for the Ukrainians than some of our systems because they're trained on them -- they operate them, they know them, they're comfortable with them. And it's a whole suite of things. And I've stayed away from naming individual systems and I think it's just better if I continue to do that. But we are in active conversations with countries about all these kinds of capabilities to see what they can do to continue to provide support to Ukraine," the official said.

Russian disinformation campaign

"In Russia, anecdotally, we see their narratives having more of an effect. But then again, they shut down independent media. The only thing available for most Russians now is state media, and so you would expect that those narratives would be more widely consumed and even more widely believed. But outside of Russia, there's little to no evidence that their information ops are working. In fact, we've seen quite the opposite," the official said.

Low Russian morale

The U.S. has anecdotal evidence of low morale in some Russian units, according to the official.

"Some of that is, we believe, a function of poor leadership, lack of information that the troops are getting about their mission and objectives, and I think disillusionment from being resisted as fiercely as they have been," the official said.

The official also said it's "noteworthy" that Russians are considering bringing in more troops and supplies only three weeks into the invasion. The Pentagon believes this is due to poor logistical planning and stronger-than-expected resistance.