The U.N. said it is increasingly concerned about the nearly 2 million internally displaced people and nearly 13 million impacted by the Ukraine-Russia conflict.

Of particular concern are supplies of food, water, medicines and other necessities that are urgently needed in the hard-hit cities of Kharkiv and Mariupol, according to UNHCR spokesperson Matthew Saltmarsh. Access to these areas remains restricted because of military operations and hazards like land mines.

The U.N. High Commissioner for Refugees is working to provide heating stations at border crossings for those who are particularly vulnerable and is also working to roll out cash assistance.

-ABC News' Zoe Magee

The number of refugees in the Ukraine crisis has increased to 2.5 million, according to the United Nations High Commissioner for Refugees.

Commissioner Filippo Grandi called the conflict "senseless" in a tweet and said that the number of displaced people inside Ukraine had reached about 2 million.

-ABC News' Zoe Magee

Russian President Vladimir Putin has ordered his defense minister to assist “volunteer” fighters to travel to Ukraine to join Russian forces there.

The order appears to relate to Russian efforts to recruit Syrian fighters that U.S. officials have said are underway.

Russia’s defense minister Sergey Shoigu claimed to Putin that 16,000 volunteers from “the Middle East” had expressed a desire to come.

Shoigu claimed that the fighters, who he said had experience fighting ISIS, wanted to come not for money but a “sincere” desire to help.

U.S. officials have said they believe Russia is recruiting Syrians experienced in urban combat from its areas held by its ally, Syrian President Bashar Al-Assad. They are reported to be being offered just a few hundred dollars.

-ABC News’ Patrick Reevell

The Senate passed a $1.5 trillion government funding bill late Thursday that includes $13.6 billion in supplemental aid to Ukraine by a vote of 68-31.

The legislation will now head to President Joe Biden's desk for his signature.

In a statement, White House press secretary Jen Psaki thanked leaders for "getting this bill done" and said Biden "looks forward to signing it into law."

"With these resources, we will be able to deliver historic support for the Ukrainian people as they defend their country and democracy," she said in part.

The supplemental Ukrainian aid is split between defense and nondefense funding. The $1.5 trillion also includes funding for many of the administration's priorities as well as sizable amounts for defense spending.

-ABC News' Allie Pecorin and Justin Gomez

The Russian forces charging toward Kyiv haven't made progress in the last day as they face Ukrainian resistance and low food and gas supply, a senior U.S. defense official told reporters Tuesday.

However, it could be a deliberate pause, the official said. "Part of the stall could be ... as a result of their own self-determined sort of pause in operations -- that they are possibly regrouping, rethinking, reevaluating," the official said.

The U.S. believes Russian forces "have committed now more than 80% of what was their pre-staged combat power," the official added.

The official said some Russian soldiers weren't told they were going into combat. The official said "not all of them were apparently fully trained and prepared."

The strong Ukrainian resistance has also hurt morale, according to the official.

Russia has now launched more than 400 missiles on Ukraine, the official said. The U.S. believes Russia has launchers that could be used for thermobaric weapons, but cannot confirm their use, the official said.

Russian forces are making the most progress in the south. Russians are attacking Kherson in south Ukraine, which "appears very much to be contested city at this point," the official said.

Russians are also approaching Mariupol in southeastern Ukraine, and while they haven't yet entered the city, "they are close enough now that they could attack Mariupol with long range fires," the official said.

Two towns on the path to Mariupol are believed to be occupied by the Russians, according to the official.

The U.S. believes the Russians hope to move north out of Mariupol up to the heavily-contested city of Kharkiv. The official said they believe Russian forces are trying to encircle Kharkiv.

The U.S. official noted that they've seen "certain risk-averse behavior by the Russian military" over the last week.

"Take the amphibious assault, for instance. They put those troops ashore a good 70 kilometers away from Mariupol because they knew Mariupol was going to be defended and they could put them ashore in an uncontested environment. And they still haven't reached Mariupol," the official said.

"They are not necessarily willing to take high risks with their own aircraft and their own pilots," the official said.

"And of course we're seeing that on the ground -- the fairly slow and steady progress that they have made, and you guys are seeing it for yourselves on the ground where ... units are surrendering, sometimes without a fight."

-ABC News' Matt Seyler