Ukraine's President Volodymyr Zelensky invited U.S. President Joe Biden to visit Ukraine during a phone call on Sunday, the Ukraine presidential office said.

Zelensky and Biden have exchanged information on the security situation around Ukraine and discussed ways of de-escalation, said a statement on the Ukrainian presidential website.

"I'm convinced that your arrival in Kyiv in the coming days, which are crucial for stabilizing the situation, will be a powerful signal and contribute to de-escalation," Zelensky told Biden.

Zelensky also stressed the importance of providing effective security guarantees for Kyiv. 

"We are ready to discuss them in different formats," he stressed. 

Zelensky stressed that Kyiv understands all current risks and is ready for "any developments." 

The Ukrainian leader thanked Washington for support, saying it contributes to strengthening the capabilities of the Ukrainian army. 

The parties also discussed the issue of increasing Ukraine's financial and energy stability amid the crisis.

According to a statement by the White House, Biden made clear in the phone conversation that the United States would "respond swiftly and decisively, together with its allies and partners, to any further Russian aggression against Ukraine."

The two leaders agreed on the importance of continuing to "pursue diplomacy and deterrence in response to Russia's military build-up on Ukraine's borders," the statement added.

Since November, Kyiv and some Western countries have accused Russia of assembling troops near the Ukrainian border with a possible intention of "invasion."

Russia denied the accusation, saying that Russia has the right to mobilize troops within its borders to defend its territory as the North Atlantic Treaty Organization's activities constitute a threat to Russia's border security.

In recent days, the United States and some other countries have advised their citizens to leave Ukraine, citing increased threats of military action.

(With input from agencies)