(CBS NEWS) -- Russian President Vladimir Putin on Wednesday said that U.S.-Russian relations had worsened during Donald Trump’s presidency.

“It can be said that the level of trust at the working level, especially at the military level, has not become better but most likely has degraded,” Putin said in an interview on Russian state television channel, Mir.

Putin’s comments came as an intense day of diplomacy began for U.S. Secretary of State Rex Tillerson, who was visiting Moscow, CBS News correspondent Margaret Brennan reports. 

Tillerson greeted his Russian counterpart Sergey Lavrov with a handshake and a message: Better relations with the U.S. require Russia to stop propping up Syrian dictator Bashar al-Assad.

The two diplomats met after the White House declassified a report detailing evidence from U.S. intelligence and other sources on Tuesday that accused Putin of a cover-up intended to “confuse” and “obfuscate” on behalf of the Assad regime.

“I have personally reviewed the intelligence, and there is no doubt the Syrian regime is responsible for the decision to attack and for the attack itself,” U.S. Defense Secretary James Mattis said.

MORE: Read, watch the full story at CBSNEWS.com