Vladimir Putin, the Russian president, said on Tuesday that US-led calls for harsher sanctions on North Korea were futile and warned that military escalation could lead to a global catastrophe, arguing that Pyongyang rightfully fears for its security.

Mr Putin called North Korea's nuclear test on Sunday “provocative” but said Kim Jong-un “definitely won't forget” the US-led military actions in Libya and Iraq.

Saddam Hussein gave up his weapons of mass destruction only to be hanged after the US invasion, he said.

“The use of any kind of sanctions in this situation is already useless and ineffective,” Mr Putin said. “They will eat grass but they won't give up (the nuclear) programme if they don't feel safe.”

Mr Putin’s comments came as concern grew that the North was planning to carry out another weapons test – possibly the launch of an intercontinental ballistic missile to mark the anniversary of its founding this Saturday.