Brink has served as the U.S. ambassador to Slovakia since 2019. She has more than two decades of experience in the Foreign Service, including stints in Georgia and Uzbekistan.
U.S. officials say Washington had approved a $165 million sale of ammunition for Ukraine's war effort, along with more than $300 million in foreign military financing.
The sun came out as Ukrainians marked Orthodox Easter in the capital, Kyiv, on Sunday with prayers for those fighting on the front lines and others trapped beyond them.
Russian forces called in airstrikes on a besieged steel factory in the southern city of Mariupol, while President Volodymyr Zelenskyy said he would meet in Kyiv with two top American officials.
Ukrainian President Volodymyr Zelenskyy plans to meet with Secretary of State Antony Blinken and Secretary of Defense Lloyd Austin on Sunday. The State Department declined to comment to NPR.
Ukrainian officials have estimated that about 2,000 of their troops are inside the plant along with the civilians sheltering in the facility's underground tunnels.
This weekend would normally be a celebratory one for Ukrainians. But Easter Sunday marks two months since the latest Russian invasion. More than 40,000 refugees have found themselves in Bulgaria.
Last month, Ukrainian forces pushed the Russians out of the village of Mala Rohan. NPR goes inside the warehouse Russia had used as temporary barracks.