Russia has warned the United States that bilateral ties are on the verge of collapsing.

In a statement, Russian Foreign Ministry said that the US ambassador to Russia John Sullivan was summoned to Moscow’s Foreign Ministry in this connection.

The Ministry said that US President Joe Biden has made unacceptable statements about his Russian counterpart in which he called Vladimir Putin a war criminal.

It said that such statements from the US president, unworthy of a statesman of such high rank