The Kremlin seemed to dare the White House to cancel the summit meeting. Mr. Peskov said that Russia continued to prepare to hold the meetings in Moscow and would until notified otherwise. He said that Russia believed in the importance of the relationship for ensuring regional and global security, but he shifted the onus to the Obama administration. “You cannot dance tango alone,” he said.

By late Thursday night, Mr. Snowden’s whereabouts remained unclear. He left the international transit zone at Sheremetyevo airport unexpectedly at 3:30 p.m. after his lawyer, Anatoly G. Kucherena, spent the day with officials from the Federal Migration Service. Mr. Kucherena delivered him a passport-like document issued Wednesday and valid until July 31, 2014, granting him status as a “temporary refugee” in Russia.

Mr. Kucherena, in an interview, said he would not disclose Mr. Snowden’s whereabouts, though he expected that he could make a public appearance soon. “I cannot give out details,” he said in an interview.

WikiLeaks said that Mr. Snowden was accompanied by one of its representatives, Sarah Harrison, who appears to have remained with him since his flight began in Hong Kong in June. Mr. Kucherena said in television interviews that while he would continue to act as counsel, he was not involved in arrangements for Mr. Snowden’s housing in Russia.

Mr. Snowden, 30, could still decide to seek permanent asylum in another country. According to Mr. Kucherena, he has not officially applied for permanent political asylum in Russia and could simply remain until he is able to fly elsewhere, though the logistics of that have been complicated by intense pressure from the Obama administration on countries to block his transit.