U.S. envoys Steve Witkoff and Jared Kushner are set to arrive in Kyiv on Sunday in their first visit to the Ukrainian capital as part of a renewed push for peace in Russia's full-scale invasion of Ukraine.

The visit follows a meeting with Russian President Vladimir Putin in Moscow on Saturday, in an attempt to revive peace talks during escalating aerial attacks by both sides.

Washington's push to end the fighting has lost momentum, with the United States focused for the past six months on the Iran war.