WARSAW, Poland (NewsNation) — Vice President Kamala Harris called for an international war crimes investigation of Russia following repeated bombing of civilians in Ukraine.

“Absolutely there should be an investigation, and we should all be watching,” she said.

Standing alongside Harris, Polish President Andrzej Duda said, “It is obvious to us that in Ukraine Russians are committing war crimes.”

Speaking from Poland Thursday, Harris thanked the Polish people and its government for their generosity for taking in more than 1 million refugees since the Russian invasion. Already, more than 2 million refugees have fled Ukraine.

The purpose of her visit is to consult with two of the leaders from eastern flank NATO nations about the growing humanitarian crisis in Ukraine. Harris said the U.S. and Poland’s stance on Ukraine invasion is “unified and is clear.”

“We will do everything together in partnership, in solidarity to do what is necessary at this very moment in terms of humanitarian and security needs,” Harris said.

Her visit comes hours after the the U.S. House passed a massive spending bill that includes $13.6 billion in aid for Ukraine and its European allies.

She called Wednesday’s Russian airstrike on a Mariupol maternity hospital that killed three people “unprovoked and unjustified.”

Harris said the Biden administration has recently deployed an additional 4,700 American troops to Poland on top of the years of rotation of about 5,000 American troops already in the country. She also confirmed the delivery of two Patriot missile-defense systems to Poland.

However, she did not budge on sending Ukraine additional Polish fighter jets that Ukranian President Volodymyr Zelenskyy says he desperately needs.

While in Poland, Harris is scheduled to meet with Ukrainian refugees who have fled to the country and with Canadian Prime Minister Justin Trudeau.