Russia has told the United States that diplomatic ties would be badly damaged and could even be broken off if Russia is declared a "state sponsor of terrorism", Tass cited a top official as saying on Friday.
Alexander Darchiyev, head of the North American department at the Russian Foreign Ministry, said if the U.S. Senate went through with plans to single out Russia, this would mean Washington had crossed the point of no return, Tass said.
Last month two U.S. senators seeking to pass a law designating Russia as a state sponsor of terrorism visited Kyiv to discuss the bill with President Volodymyr Zelenskiy.
Darchiyev said if this passed, it would cause "the most serious collateral damage for bilateral diplomatic relations, to the point of downgrading and even breaking them off," Tass quoted him as saying.
"The American side has been warned," he added.