MOSCOW — Looking to secure Russia’s help on an array of issues, from Syria to nuclear arms cuts, President Obama at the Group of 8 summit meeting last week talked of his hope for “a constructive cooperative relationship that moves us out of a cold war mind-set.”

But there are times when the old rivalry is as fierce as ever, when spying and counter-spying are a given. The arrival in Moscow of Edward J. Snowden was such a moment.

Ignoring demands by the White House, and even a personal entreaty by Secretary of State John Kerry, to intercept Mr. Snowden and return him to the United States, where he is accused of disclosing classified intelligence, the Russian government denied having any information about him.

The denials echoed Monday on state-controlled television and on news agencies close to the Kremlin, even as Russian police surrounded the Aeroflot jet that would presumably ferry Mr. Snowden to Cuba. They were repeated even as WikiLeaks, the anti-secrecy group that is helping Mr. Snowden, said he had special travel papers from Ecuador for safe passage through Russia.