Moscow: Russia on Monday summoned the US ambassador in protest after President Joe Biden branded Russian leader Vladimir Putin a “war criminal” for Moscow’s actions in Ukraine, saying he had endangered ties. “Such statements by the American president, which are not worthy of a high-ranking statesman, have put Russian-American relations on the verge of rupture,” the foreign ministry said in a statement. The statement said ambassador John Sullivan had been handed a formal letter of protest over “recent unacceptable statements” made by Biden. He was warned that “hostile actions taken against Russia would receive a firm and decisive response,” the ministry said. Biden described Putin as a “war criminal” in remarks to reporters last week, amid heavy fighting in Ukraine after Moscow sent tens of thousands of troops into the pro-Western country. In Washington, State Department Spokesman Ned Price rebuffed Moscow’s complaint. “They’ve given their version of events,” he said. “I think it is worth repeating that Russia is carrying out an unprovoked and unjustified war on Ukraine and we are seeing clear evidence that they are intentionally targeting civilians and committing indiscriminate attacks,” he said. Biden’s comments last week “speak to the horror, of the brutality Russia has unleashed on an innocent neighbor, an innocent neighbor that posed absolutely no threat or security risk to Russia.” He said that it was important to keep open channels of communication, “, especially during times of conflict.” Price said Sullivan seized the occasion to complain that US diplomats were not being granted access to Americans being held by Russia. Those include star professional basketball player Brittney Griner, who was detained in Moscow airport on February 17 on charges of carrying vape cartridges that contained cannabis oil in her luggage. Two other Americans, Paul Whelan, and Trevor Reed are also being held on what Washington says are false or trumped-up charges. “We have consistently and improperly been denied access for months. This is completely unacceptable,” Price said.