Saturday marks exactly two years since Russia invaded Ukraine.

With Washington wavering on continued support for Kyiv amid stepped-up Russian aggression, Ukrainian President Volodymyr Zelenskyy has called on a visiting US Senate delegation to stay the course.

Zelenskyy met the Democratic senators led by Majority Leader Chuck Schumer in the western Ukrainian city of Lviv on Friday.

Following the meeting, Zelenskyy said in a video address that the United States' military support is crucial for Ukraine's defense.

Schumer later told reporters that Zelenskyy had said that Ukraine would not survive without US support.

Additional US military aid has been suspended due to opposition from Republican lawmakers and there is no prospect of approval of an emergency budget bill worth more than 95 billion dollars, including support for Ukraine.

Meanwhile, Russia's defense ministry said on Saturday that Defense Minister Sergei Shoigu had inspected frontline units in Ukraine. It said he was briefed about the battle in the eastern city of Avdiivka, a Ukrainian stronghold which Russian forces captured earlier this month.