US President Joe Biden and Russian President Vladimir Putin have held a phone conversation over the situation in Ukraine.
During the call, which lasted for about one hour,
the two leaders discussed the situation in Ukraine and related security issues.
The white house said Biden made it clear to Putin that
while the United States remains prepared to engage in diplomacy, it is "equally prepared for other scenarios".
The Kremlin said Russia has not received a substantive response from the US on security guarantees.
The United States and its allies are urging their citizens to leave Ukraine right away,
citing what they called "increased threats of Russian military action against Ukraine".
Washington has been releasing intelligence which it claims is proof that Russia is prepared to mount a military aggression anytime now.
But Moscow has accused Western nations of spreading lies to distract from their own aggressive acts.