President Obama’s scheduled trip to Moscow to meet with Russian President Vladi­mir Putin in September is in limbo because of uncertainty surrounding National Security Agency leaker Edward Snowden, who fled to Russia and is seeking asylum there.

In addition to the Snowden case, relations between the United States and Russia have become strained in recent weeks over the ongoing conflict in Syria, disputes over nuclear weapons and concerns about the Putin government’s treatment of dissidents.

The White House announced in June that Obama would meet with Putin in Moscow around the time of the annual Group of 20 nations summit, which Russia is hosting Sept. 5-6 in St. Petersburg.

White House press secretary Jay Carney declined repeatedly this week to say whether Obama still plans to visit Moscow.

“The president intends to travel to Russia for the G-20 summit,” Carney told reporters on Wednesday. “And I have no further announcements to make beyond what we’ve said in the past about the president’s travel to Russia in the fall.”

Pressed a second time, Carney acknowledged that he was being “deliberately vague.”

This would not be the first canceled Obama-Putin meeting. Last year, when Obama hosted the Group of 8 summit at Camp David, Putin stayed home, saying he was too busy in Moscow finalizing his new cabinet.

The United States has revoked the passport of Snowden, the former NSA contractor who leaked classified details of government intelligence and surveillance operations to journalists. He has been staying in the transit zone at Moscow’s airport for several weeks.

The Obama administration could be leaving the Moscow visit up in the air as negotiating leverage, hoping to persuade the Russians to help return Snowden to the United States, where he would face charges.

But Carney has stopped short of directly threatening a cancellation, and his rhetoric about Russia in general has been relatively low-key. Asked on Wednesday whether there would be consequences for Russia if Snowden is not returned, Carney demurred.

“We are working with them through normal channels and having conversations with Russian government officials at all levels about this matter,” he told reporters. “I am not going to get ahead of that process.”

Keeping the Putin meeting uncertain also could help placate Republican critics on Capitol Hill, some of whom have publicly called for a more aggressive posture on Russia.

Sens. John McCain (Ariz.) and Lindsey O. Graham (S.C.), two of the most outspoken critics, met privately with Obama for nearly 90 minutes Wednesday to discuss a range of foreign policy issues.

Publicly, Graham has urged Obama to demand a change in venue for the G-20 summit and also has suggested a U.S. boycott of the 2014 Winter Olympic Games in Sochi, Russia.

Carney said neither idea is on the table. When a reporter asked whether Obama believed a boycott was a bad idea, Carney said, “Yes, but it’s not one that is an issue.”