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."