White House national security adviser Jake Sullivan spoke to his Russian counterpart, Nikolai Patrushev, on Wednesday and warned Russia against using chemical or biological weapons in Ukraine, according to the White House.
Sullivan “warned General Patrushev about the consequences and implications of any possible Russian decision to use chemical or biological weapons in Ukraine,” White House National Security Council spokeswoman Emily Horne said in a statement.
Sullivan also reiterated the United States’ “firm and clear” opposition to Russia’s invasion of Ukraine and vowed to continue imposing penalties on Russia in coordination with allies, she said.
“Mr. Sullivan told General Patrushev that if Russia is serious about diplomacy then Moscow should stop attacking Ukrainian cities and towns,” Horne said.
White House press secretary Jen Psaki later told reporters that the call was the most senior discussion between the U.S. and Russia since Secretary of State Antony Blinken last spoke to Russian foreign minister Sergey Lavrov. That call took place in February, before Russian President Vladimir Putin ordered the large-scale invasion of Ukraine three weeks ago.
The last disclosed call between Sullivan and Patrushev occurred on Nov. 17. Sullivan has also periodically engaged with Putin’s foreign policy adviser, Yuriy Ushakov. The White House did not offer a particular reason for why Sullivan called Patrushev, who is the secretary of the Russian Security Council, on Wednesday.
Biden administration officials have warned publicly for the past week that Russia could use chemical or biological weapons in Ukraine, saying that Russia is spreading false claims about the U.S. supporting chemical weapons development in the country in order to create a pretext for further aggression.
“We have real concerns that Russia could use a chemical weapon, another weapon of mass destruction,” Secretary of State Antony Blinken said on CNN Tuesday. “This is something we’re very focused on.”
Psaki said the U.S. and Russia have maintained direct and indirect contacts through their embassies, as well as a military deconfliction channel.
The U.S. requested the phone call primarily to warn Russia there would be consequences if it used chemical weapons, she said.
“We wanted to have a direct conversation of what the consequences would be of further escalatory action,” Psaki said.
The Biden administration has said the U.S. would impose severe consequences on Russia if it took such a step, but officials have declined to lay out specific consequences.
Sullivan’s phone call with Patrushev took place hours before President Biden announced $800 million further U.S. security assistance to Ukraine as it fights the Russian invasion.
Updated at 4:32 p.m.