The UN Security Council on Monday strongly condemned North Korea after a failed missile launch, threatening further measures against Pyongyang.

North Korea tested a medium-range Musudan missile on Saturday, the latest in series of launches in defiance of UN resolutions. The rocket exploded soon after lift-off.

In a unanimous statement backed by China, Pyongyang's ally, the council "strongly condemned the most recent failed ballistic missile launch," branding it a "grave violation" of North Korea's international obligations.

Council members agreed to "closely monitor the situation and take further significant measures," the statement said.

The United States and China are drafting a new sanctions resolution that the Security Council agreed last month to pursue after Pyongyang carried out its fifth and most powerful nuclear test to date.

North Korea has been hit by five sets of UN sanctions since it first tested a nuclear device in 2006.

After Pyongyang carried out its fourth nuclear test, the council in March adopted the toughest sanctions resolution so far, targeting North Korea's trade in minerals and tightening banking restrictions.

Negotiations on the new sanctions measure are focussed on closing loopholes and zeroing in on North Korea's nuclear and ballistic missile technology industry, according to Security Council diplomats.

North Korea has carried out more than 20 missile launches since the March resolution was adopted.