BRUSSELS – Defense Secretary Jim Mattis says the U.S. is not ready to collaborate militarily with Russia, appearing to close the door for now on any effort to work more with Moscow in the fight against Islamic State militants in Syria.
Mattis says the U.S. will continue to engage politically with Russian President Vladmir Putin's government to try to find common ground. He says Russia must "prove itself" and abide by international law.
The U.S. ceased military to military relations with Russia in the wake of Moscow's 2014 annexation of Ukraine's Crimea region.
As a candidate, President Donald Trump repeatedly praised Putin, saying he wanted a new era of cooperation with Moscow.
Putin called Thursday for increased intelligence cooperation with the U.S. and NATO.