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 Tuesday on Day 27:
Russian forces estimated below 90% combat capability for first time
"Let me remind, that is of the combat power that they assembled in Belarus, and in the western part of their country prior to the invasion, it is not an assessment of all Russian military power," the official said. "But we assessed it for the first time they may be just a little bit below 90% on that. And no indications, no tangible indications of reinforcements being brought in from elsewhere in the country, no tangible indications of foreign fighters that have flown into the country ... no indications that they've moved in foreign fighters from Syria or elsewhere.
"And on resupply, again, no tangible indications that they are making an effort to resupply from outside the theater there that they're pulling in from elsewhere around the around Russia. But we do continue to see indications that they are having these discussions and that they are making those kinds of plans."
"It's our assessment that as they look at reinforcements, it's probably the most likely scenario that they would want to pull in from places not inside Russia. I'd remind you that of the battalion tactical groups that Mr. Putin has available to him across Russia, he's used about 75% in this particular operation. So, I think our assumption would be he'd pull from outside the country first, but that's an assumption and I really don't want to get any more detailed than that," the official said.
On whether troops in Belarus were massing on border with Ukraine, this official said, "I don't have anything specifically with respect to Belarusian intentions, we're watching this as closely as we can. But nothing specific to report to in terms of Belarusian activity towards moving in."
Forces still stalled outside Kyiv, frostbite now an issue, missiles fired top 1,100
For the most part Russian troops remain stalled around Kyiv at the same distances we've heard for more than a week, the official said. "We haven't seen any major repositioning by them around Kiev. Again, it's kind of been static 15 kilometers or so to the north, west and 30 kilometers to the to the east. They just haven't. We have not seen a lot of movement on their part."
The logistical and resupply issues continue to plague Russian troops with the official noting that Russia now has concerns about fueling the ships in the Black Sea.
In addition to lack of food and equipment Russian troops are now enduring frostbite. "We've picked up some indications that some of their soldiers are suffering from frostbite because they lack the appropriate cold weather gear for the environment" said the official who added that some of those soldiers have been taken out of the fight as a result.
The number of Russian missiles fired in Ukraine remains above 1,100, the official said.
Ukrainian troops on offensive
"We have seen indications that the Ukrainians are going a bit more on the offense now," Pentagon press secretary John Kirby said at a briefing later on Thursday. "They have been defending very smartly, very nimbly, very creatively in places that they believe are the right places to defend and we have seen them now in places particularly in the south, near Khersan, they have tried to regain territory. Again we don't have great fidelity of tactical movements, but we have seen them, make these make these efforts."
He noted how the Ukrainians had said a few days ago that they were planning counterattacks and "I think we have seen indications that they're that they're moving in that direction."
He said later, "We do assess it in some places they are they are attempting to take back territory that the Russians have captured or occupied."
Russian siege of Mariupol
"The Ukrainians are fighting very, very hard to keep Mariupol from falling," said the official. The official said Ukrainian forces have mounted a strong resistance inside of Mariupol against the "significant number" of Russian forces that have made their way into the city including Russian separatist forces from the Donbas. For the most part, the Russian forces now pressing on Mariupol are forces that came south from Donetsk.
The significant artillery and long-range bombing of Mariupol continues, but what's news is that the U.S. has observed over the last 24 hours "that the Russians have likely been firing into the city from the sea from the Sea of Azov" where the Russians have seven ships.
The official said the U.S. assessed that the Russian push toward Mariupol is intended to be the "southern pole" of an effort by the Russians to cut off Ukrainian troops in the Donbas. "So that Ukrainian forces can't ... come to the defense of cities further to the west, including Kyiv. So, Mariupol serves as an anchor for that effort, if you will, on the southern stretch of Ukraine."
"A lot of significant fighting going on. Ukrainians are not giving up on Mariupol. They're fighting hard to prevent that. I'm sure that they don't need to be reminded about the importance of that city to this entire effort," the official said.
In the Black Sea, the official said, there was "no indication that there is an imminent amphibious assaults on or near Odesa and again we did not observe, at least from the navy side, we did not observe showing over the last 24 hours."
The Russians have 21 ships in the Black Sea. Twelve of them are surface combatant ships and nine of them are amphibious ships.
Ukraine invasion raises questions about US troops in eastern Europe
Kirby acknowledged that Russia's invasion of Ukraine has changed the security situation in Europe and that NATO's meeting this week may need to address new questions such as whether to keep troops in eastern Europe in the long term. "We've got to think about it in a completely different way, no matter how this all ends up," Kirby said.
Kirby said he couldn't get ahead of the NATO meeting and President Joe Biden's participation but recalled that during Defense Secretary Lloyd Austin's trip to NATO last week that the alliance was "taking steps to bolster deterrence and readiness" in the wake of Russia's invasion, including the formation of new battle groups. "The degree to which they exist long term is really going to be an alliance decision, not something that the United States will be able to decide unilaterally," said Kirby.
Noting that the U.S. has boosted its troop levels in Europe from 80,000 to 100,000, Kirby said he couldn't predict the future but "I can tell you that the secretary wants to preserve his options to a unilaterally be able to continue to bolster the eastern flank."
He added, "We're not sure where this is going to go but the secretary is convinced that wherever it goes, the security environment on the European continent is now changed. And we've got to think about it in a completely different way, no matter how this all ends up."