Moscow, Reuters—The Kremlin said on Wednesday a spy dispute could impede efforts to improve ties with the United States, but did not threaten any more action after the expulsion of a diplomat accused of trying to recruit a Russian agent.

President Vladimir Putin’s spokesman Dmitry Peskov made his first comments on the case as US Ambassador Michael McFaul discussed it with the Russian Foreign Ministry. McFaul, who was summoned on Tuesday, made no comment as he left the meeting.

“It (the attempted spy recruitment) does not contribute to the future process of strengthening mutual trust between Russia and the United States and putting our relations on a new level,” Peskov told Itar-Tass news agency.

He did not comment in detail on the incident and appeared to avoid any inflammatory language over the detention and expulsion of Ryan Fogle, a third secretary at the US Embassy in Moscow who was detained on Monday night.

The incident came at an awkward time for Washington and Moscow as they try to improve relations and bring the warring sides in Syria together for an international peace conference.

But there is little sign that either country wants the affair to go beyond a minimum response.