The U.S. is considering sending a high-level official to Kyiv.

The United States is considering whether to send a high-level official to Kyiv, Ukraine’s capital, in the days ahead as a sign of support for Ukraine in its war with Russia, according to a person familiar with the internal discussions.

President Biden and Vice President Kamala Harris have both made high-profile visits over the past month to countries neighboring Ukraine as the war raged. And other top American officials have made similar visits, some coming close to the border. But no American official has publicly visited Ukraine since Russia launched its invasion in late February.

It is highly unlikely that Mr. Biden or Ms. Harris would go to Kyiv, according to the person familiar with the deliberations. The security requirements for the president or vice president in a war zone are enormous and would require a huge number of American personnel and equipment to make the trip.

But it is possible that another official — perhaps a cabinet secretary or senior member of the military — could make the trip safely with a smaller security entourage.

Top officials — including some world leaders — from other nations have made official visits to the Ukrainian capital since the war began. Boris Johnson, the prime minister of Britain, made a surprise visit to Kyiv on Saturday. The presidents of Poland, Lithuania, Latvia and Estonia visited Kyiv on Wednesday.

A possible visit by a senior U.S. official, which was earlier reported by Politico, would be intended as another show of solidarity with President Volodymyr Zelensky of Ukraine. But it would also be a high-risk mission, putting Americans in harm’s way and potentially risking a direct confrontation with Russian forces that Mr. Biden has repeatedly vowed to avoid.

No decision has been made, and the administration is unlikely to announce a visit in advance, given concerns about security. Previous visits by senior American officials to other war zones, such as Iraq and Afghanistan, were typically not announced until after the official had arrived in the country — and sometimes not even until after the official had left.