National Security Adviser Jake Sullivan made an unannounced visit Friday to Kyiv, where he met Ukrainian President Volodymyr Zelensky and other top officials.
Sullivan underscored US support for Ukrainians "as they defend their sovereignty and territorial integrity," said Adrienne Watson, a spokesperson for the National Security Council, in a statement.
In Kyiv, Sullivan announced an additional $400 million security assistance package to Ukraine. It includes refurbished T-72 tanks and drones, along with refurbished surface-to-air missiles.
He also affirmed the US will continue to provide economic and humanitarian assistance to Ukraine:
"The United States is going to be with Ukraine for as long as it takes in this fight. There will be no wavering, no flagging, no flinching in our support as we go forward."
Sullivan added that the war could easily end if Russia chose to stop fighting and ceased its occupation.
"And that's precisely what it should do from our perspective," he told reporters.
Zelensky said he was grateful to Sullivan for his support for Ukraine.
"I had the honor of presenting Jake with the Order of Prince Yaroslav the Wise of the II degree on behalf of the entire Ukrainian people for strengthening interstate cooperation, supporting state sovereignty and territorial integrity of Ukraine," the Ukrainian president said in a Telegram post.