U.S. President Joe Biden called Russian President Vladimir Putin a war criminal on Wednesday, prompting the Kremlin to say the comment was ¡°unforgivable¡± as the war in Ukraine raged for a 21st day despite talk of compromise in peace negotiations.

Moscow has yet to capture any of Ukraine¡¯s biggest cities following its incursion that began on Feb. 24, the largest assault on a European state since World War II that has raised fears of wider conflict in the West unthought-of for decades.

Putin on Wednesday said the Kremlin was ready to discuss neutral status for its neighbor but said what he calls a ¡°special military operation¡± to ¡°demilitarize and denazify¡± Ukraine was ¡°going to plan.¡±