RIA Novosti reports this with reference to Bloomberg.
It is noted that the message was signed by Democrats Ben Cardin, Dick Durbin and Chris Koons, as well as Republicans Mitt Romney, Marco Rubio and Roger Wicker.
Senators have called for the use of the Sergei Magnitsky Rule of Law and Accountability Act or the Chemical and Biological Weapons Control Act.
Earlier, Russian leader Vladimir Putin, during a meeting of the Valdai Discussion Club, spoke about his appeal to the Prosecutor General's Office of Russia with a request to allow Alexei Navalny to leave for treatment in Germany.