Washington - (AFP) - The United States "firmly" condemned Tuesday the numerous Russian strikes on Ukrainian regions, and considered them "deepening the concerns" of the G20 countries meeting in Indonesia.

"The Russian strikes deepen concerns in the G-20 about the destabilizing impact of (Russian President Vladimir) Putin's war," White House National Security Adviser Jake Sullivan said in a statement.

The Ukrainian army confirmed that Russia had fired "about" a hundred missiles at the main energy infrastructure in several regions of the country, and at residential buildings in the capital, Kiev.

"We will not lose sight of the fact that while G20 leaders meet in Bali to discuss issues important to the lives and livelihoods of people around the world, Russia has decided to threaten these lives and destroy key infrastructure in Ukraine ," Sullivan added.

"The United States and our allies and partners will continue to support Ukraine with what it needs to defend itself, including air defense," the statement added.