Russia has barred a second senator from entering the country as Moscow denies visas for American lawmakers critical of President Vladimir Putin while President Trump backs him on the world stage.

“While I’ve been a tough critic of the Kremlin, I also believe it’s important to maintain dialogue especially during moments of tension,” Connecticut Democrat Chris Murphy, a member of the Senate Foreign Relations Committee, said Tuesday. “Unfortunately, the Russian government is further isolating their country by blocking our visit and several others in recent months.”