WASHINGTON, February 20. /TASS/. The US notified Russia that US President Joe Biden was heading to Kiev a few hours before he left the US capital, White House national security adviser Jake Sullivan told reporters on Monday.

"We did notify the Russians that President Biden would be traveling to Kiev. We did so some hours before his departure for deconfliction purposes," Sullivan told reporters.

He didn’t say how Moscow responded to the notification.

According to Sullivan, the US president made the final decision to travel to Ukraine after conferring with his aides on February 17. The visit had been prepared for several months by a handful of his aides and staff from the Pentagon and intelligence services. Biden was regularly briefed on the preparations, including assessments of potential threats.

"This was a historic visit, unprecedented in modern times, to have the president United States visit the capital of the country of war, where the United States military does not control the critical infrastructure," Sullivan said.

He said the US president was accompanied in Ukraine by just some of his close aides, medical staff and a security detail. Sullivan said Biden wanted his visit to send a clear message of an unwavering US support for Ukraine.

According to the US official, Biden and Ukrainian President Vladimir Zelensky discussed the problems Ukraine is facing in the fields of energy and infrastructure, the provision of economic support to the country, its humanitarian needs, and the special session of the UN General Assembly dedicated to the Ukrainian issue, which will resume its work on February 22.

Biden's trip to Kiev on Monday, which was not officially announced in advance, is his first visit to Ukraine since his election as US president. While in Kiev, Biden pledged further military assistance to Ukraine. He spent roughly five hours in the Ukrainian capital.