Russia on Saturday said it was ready to resume anti-terrorism cooperation with the United States as America marked the 20th anniversary of 9/11.

In a statement released by Moscow's diplomatic mission in Washington, ambassador Anatoly Antonov said Russia was grieving together with the United States and proposed reviving cooperation on the fight against terrorism despite a litany of problems in bilateral ties.

The Moscow envoy said Russia was ready to resume bilateral dialogue on counterterrorism which was carried out under the auspices of the foreign ministries in 2018-2019.

"The Russian side is ready to revive the mentioned format. This is our natural priority," Antonov said in a statement posted on the Facebook page of the Russian embassy.

"We should put aside all contradictions and disputes and cooperate for the benefit of security and prosperity of not just Russia and the United States, but all of humanity," Antonov added.

Russia, he said, was grateful to the United States for sharing information that helped prevent attacks in Saint Petersburg in 2017 and 2019.

Troubled bilateral relations have rapidly deteriorated further after Joe Biden increased pressure on the Kremlin since becoming US president in January. 

In May, Russia formally labelled the United States an "unfriendly state."

On Friday, Moscow summoned US ambassador John Sullivan over what it said was interference of US tech giants in Russian parliamentary polls due next week.