Treasury secretary Janet L. Yellen arrived in Kyiv for an unannounced visit on Monday, as the US disbursed more than $1 billion in additional economic assistance to Ukraine a year after the start of Russia’s full-scale invasion.

The trip — a rare journey by a top US economic diplomat into an active war zone — is intended demonstrate the Biden administration’s commitment to helping Ukraine keep its basic government functions operating.

A treasury official said that Yellen would hold “meetings and engagements” while in Kyiv, where she announced the transfer of $1.25 billion of economic and budgetary assistance from the US to Ukraine.

During her visit, she will stress that helping Ukraine maintain government services is critical to its ability to succeed on the battlefield.

Yellen’s trip — three days after the anniversary of the invasion — follows a surprise visit to Ukraine by President Joe Biden earlier this month.

The high-profile visits have come amid an intensifying political debate in the US about whether the country can afford to continue to provide aid to Ukraine.

Yellen said last week that American support for Ukraine would be “lasting and unconditional” and argued that the US could bear the economic costs.

“The war is having an adverse effect on the entire global economy,” Yellen said in an interview with The New York Times on Saturday.

“Providing the support that’s necessary for Ukraine to win this and bring it to an end is certainly something that we really can’t afford not to do.”

As treasury secretary, Yellen has been involved in crafting the sanctions that the US has imposed on Russia in the last year to put pressure on its economy. She also devised the price cap that the US and its allies in the G7 nations enacted to limit the price at which Russian oil can be sold.

The US started disbursing $10 billion in grant financing to Ukraine last week for healthcare, education, and emergency services.

The funds were part of the $45 billion aid package that Congress approved last December.

The IMF has estimated that Ukraine needs about $5 billion a month in financial support.

New York Times News Service