America's patience with Russia's stance on the fugitive whistleblower Edward Snowden ran out as President Barack Obama abruptly cancelled a summit with President Vladimir Putin.
The White House called off the meeting in Moscow next month in protest at Russia's decision to grant Snowden temporary asylum and the "lack of progress" in talks on Syria, missile defence and human rights.
The diplomatic snub reflected United States fury at the Kremlin for harbouring the former spy but also a year of growing frustration with what Obama called Russia's "Cold War mentality".
Ben Rhodes, the White House deputy national security adviser, said: "It was the unanimous view of the President and his national security team that a summit did not make sense in the current environment."
The Kremlin said it was "disappointed" at the decision, which, it said, showed the US was not ready to deal with Russia "on an equal basis". Yuri Ushakov, Putin's foreign policy adviser, said: "It is clear that the decision is linked to the situation over the employee of the American special services Snowden which was absolutely not created by us."
Obama will still travel to St Petersburg for the G20 summit with other leaders but will not go to Moscow for a one-on-one with Putin. Aides said there were no proposals for the two presidents to meet on the sidelines of the G20.
In an interview on The Tonight Show on Wednesday, Obama gave an unusually frank assessment of his frosty relationship with Putin and said he was "disappointed" Russia had not handed over Snowden.
"There have been times where they slip back into Cold War thinking and a Cold War mentality," Obama said, noting that Putin was the former leader of the FSB, successor to the KGB. Asked about recent tense joint appearances, Obama said the Russian leader's "preferred style" was "sitting back and not looking too excited".
"Part of it is he's not accustomed to having press conferences where you've got a bunch of reporters yelling questions at you," Obama said in a thinly veiled barb at Putin's crackdown on media critics.
Steven Pifer, a senior fellow at the Brookings Institute, said the White House sensed the meeting would not lead to progress on Syria or US plans for a missile shield in eastern Europe.
Russia said last night the invitation to Obama remained open. John Kerry, the US Secretary of State, and Chuck Hagel, the Secretary of Defence, are still due to meet their Russian counterparts in Washington tomorrow.