WASHINGTON, October 1. /TASS/. Chairman of the US Senate’s Foreign Relations Committee Jim Risch (R, Idaho) and its Senior Democrat Bob Menendez (D, New Jersey) are calling on the Washington administration to launch an investigation into the alleged poisoning of Russian opposition figure Alexei Navalny, the committee’s press service reported Wednesday that the request is contained in a letter sent to US President Donald Trump.

"We are writing to respectfully request that you consider whether the government of the Russian Federation used chemical or biological weapons in violation of international law or against its one of its own nationals and thus should be subject to sanctions contained in the statute," the senators wrote."Mr. Navalny’s poisoning is particularly disturbing as a Novichok agent was also used in the March 2018 attack on Sergei Skripal in Salisbury, England. In that instance, your administration concluded that the Russian government was behind the attack and thus subject to sanctions. The United States must again make clear that any such behavior is not acceptable," they concluded.