This combination of pictures created on December 06, 2021 shows US President Joe Biden during a signing ceremony at the White House in Washington, DC on November 18, 2021 and Russian President Vladimir Putin in a congress of the United Russia party in Moscow, on December 4, 2021. AFP
Karen Donfried will be in Kiev and Moscow from Monday to Wednesday to meet senior government officials "and to reinforce the United States' commitment to Ukraine's sovereignty, independence, and territorial integrity", it added.
"Assistant Secretary Donfried will emphasise that we can make diplomatic progress on ending the conflict in the Donbas through implementation of the Minsk agreements in support of the Normandy Format," a statement read.
The 2015 Minsk Agreement aimed at halting fighting inside Ukraine, bolstered by the Normandy Format -- a diplomatic push by France and Germany to end the conflict.
Donfried will be in Brussels Wednesday and Thursday "to consult with NATO allies and EU partners on efforts to pursue a diplomatic solution" to the stand-off.
US President Joe Biden and his Russian counterpart Vladimir Putin held a virtual summit earlier this week, in which Washington threatened Moscow with unprecedented sanctions if Ukraine is attacked.
Russia's build-up of up to 100,000 troops on the border with Ukraine has topped the agenda at this weekend's G7 foreign ministers' summit in Liverpool, northwest England.
Russia says the deployment is a defensive measure against a possible shift by the one-time Soviet republic towards NATO.
Biden had said after the call with Putin that they would instruct their teams to work on follow-up talks.