The conference, founded in 1962, has become an annual opportunity for world leaders to discuss the most pressing issues of the day.

Putin told senior security officials from around the world that nations were "witnessing an almost uncontained hyper-use of force in international relations."

"One state, the United States, has overstepped its national borders in every way, " the Russian president said. "This is very dangerous. Nobody feels secure anymore because nobody can hide behind international law. This is nourishing an arms race with the desire of countries to get nuclear weapons."

These comments may well be remembered as a turning point in international relations and a sign of a more assertive Russia.

Western leaders in the audience, including German chancellor Angela Merkel, looked decidedly glum-faced when President Putin had finished.

Earlier, Mrs Merkel told delegates there was "no way around" the need for Tehran to accept demands from the UN and nuclear watchdog, the International Atomic Energy Agency (IAEA).

"What we are talking about here is a very, very sensitive technology, and for that reason we need a high degree of transparency, which Iran has failed to provide, and if Iran does not do so, then the alternative for Iran is to slip further into isolation, " she said.