A bipartisan group of U.S. senators announced Saturday that they are traveling to Poland to meet with Polish officials and visit refugee sites to reaffirm the United States' commitment to Poland, Ukraine and other allies in response to Russian President Vladimir Putin’s invasion of Ukraine.

The group is made up of Sens. Rob Portman, R-Ohio, Amy Klobuchar, D-Minn., Roger Wicker, R-Miss., and Richard Blumenthal, D-Conn.

The group was also expected to meet with the U.S. 82nd Airborne Division stationed in Poland on the trip this weekend.

"The Polish people continue their unwavering support for NATO after 23 years of fighting alongside the U.S. and our allies. This bipartisan delegation will send a clear message that the U.S. is thankful for their support of Ukraine and their offer of providing fighter jets, as the people of Ukraine continues to endure brutal Russian atrocities," Portman said in a statement.

Echoing U.S. support for Ukraine, Blumenthal said, "As Putin continues his brutal, savage invasion, I’m traveling with a bipartisan group of Senators to the Ukrainian border in Poland to see first-hand the heartbreaking, exploding humanitarian crisis — and learn how America can magnify its military assistance to brave Ukrainian freedom fighters."

-ABC News' Trish Turner

Vice President Kamala Harris on Saturday re-emphasized the U.S.' commitment to defend NATO allies and said, "Our collective resolve has been strengthened” since Russia’s invasion of Ukraine.

"The United States stands firmly with the Ukrainian people [and] in defense of the NATO alliance," Harris said at the DNC Winter Meeting, hours after returning from her trip to Poland and Romania.

"Russia's invasion threatens not just Ukraine's democracy, it threatens democracy and security across Europe and by extension when democracy is threatened, anywhere, it threatens us all," Harris said.

Harris recalled her meeting with the presidents of both nations and how she met with refugees from Ukraine, who she said “feel very alone."

"I told them people around the world stand with them and they are not alone," Harris said.

-ABC News' Justin Gomez

Ukrainian President Volodymyr Zelenskyy told reporters Saturday that Russia would have to carpet-bomb Kyiv and kill all its residents to be able to conquer the capital city.

"They will come here only if they kill us all," Zelenskyy said. "If that is their goal, let them come."

-ABC News' Jason Volack

Ukrainian President Volodymyr Zelenskyy said that Ukraine lost 1,300 troops and claimed that Russia has lost 12,000 troops, to reporters Saturday.

"I can't say that I'm happy about their losses because it's not who I am. We're talking about human lives here, and those soldiers were brought to the war as cannon fodder, brainwashed and confused," Zelenskyy said.

Zelenskyy also commented on the humanitarian corridors for the evacuation of civilians, saying the most successful corridor has been out of Sumy where tens of thousands were evacuated.

"It's a very difficult process and sometimes we have to invent unorthodox methods to facilitate that, because the Russians almost never observe cease-fire to allow evacuation of civilians," Zelenskyy said.

Zelenskyy also commented on discussions with Russia, saying he has been requesting direct talks at the highest level for over two years.

"At least we can see some progress now in that they also start to agree that dialogue is needed. But of course we would seek broader involvement of other world leaders, because in any talks about future firm security guarantees for Ukraine we will never trust only Moscow after such a bloody war it unleashed," Zelenskyy said.

-ABC News' Guy Davies