"I condemn North Korea's ballistic missile launches today, in breach of UN Security Council Resolutions," Foreign Secretary Miliband said in a statement.

"These latest provocations will only strengthen our resolve as we work with international partners to implement the robust measures in the UN Security Council Resolution passed unanimously last month," he added.

North Korea test-fired seven missiles off its east coast on Saturday, South Korean officials said, in an act of defiance apparently timed for the US Independence Day holiday.

The launches further fuelled regional tensions after the communist state's nuclear test in May, which coincided with the US Memorial Day holiday.

They came as Washington seeks support for tough enforcement of United Nations sanctions aimed at shutting down the North's nuclear and missile programmes.

The ballistic missiles -- which the North is banned from firing under UN resolutions -- were launched between 8:00 am (2300 GMT Friday) and 5:40 pm into the Sea of Japan (East Sea), Seoul military officials said.

It was the biggest salvo of ballistic weaponry since the North fired a long-range Taepodong-2 and six smaller missiles on US Independence Day in 2006.

"We will work to ensure North Korea desists from any further launches and eventually return to the negotiating table," Miliband added in his statement on Saturday.

"In the meantime it is vital that North Korean capacity is contained and tension on the Korean peninsular kept at manageable levels."