There have been a number of missile tests by North Korea

North Korea crisis: North test-fires ballistic missile

It apparently exploded seconds after lift-off, the South Korean military was quoted as saying by Yonhap news agency. The US military said the missile did not leave North Korean territory.

It was fired from a site in South Pyeongan province north of Pyongyang in the early hours of Saturday local time, South Korea said.

The type of missile is not yet known.

US President Donald Trump tweeted: "North Korea disrespected the wishes of China & its highly respected President when it launched, though unsuccessfully, a missile today. Bad!"

So far there has been no word from North Korea.

Tensions in the region have increased lately, with both North and South Korea conducting military exercises.

North Korea has made repeated attempts to miniaturise nuclear warheads and fit them on long-range missiles capable of reaching the US.

Tillerson's warning

"North Korea fired an unidentified missile from a site in the vicinity of Bukchang in Pyeongannam-do (South Pyeongan Province) early this morning," the South Korean Joint Chiefs of Staff (JSC) said in a statement, Yonhap reports.

It added that the missile apparently exploded, just seconds after the launch.

Meanwhile, Commander Dave Benham, a spokesman for US Pacific Command, said the "launch occurred near the Pukchang airfield (north of Pyongyang)".

He added that the missile did not leave North Korean territory and did not pose a threat to North America.

US ready for 'military action, if necessary' against N Korea

The launch occurred a matter of hours after the US Secretary of State Rex Tillerson called on the rest of the world to help force North Korea to give up its nuclear ambitions.

Speaking at the UN Security Council, Mr Tillerson warned of "catastrophic consequences" if the Council did not act, saying it was "likely only a matter of time before North Korea develops the capability to strike the US mainland".

The US would use military force if necessary, he said.

Mr Tillerson accused Council members of not fully enforcing existing sanctions against the North, and called on China in particular to leverage its trade links as influence.

But the Chinese Foreign Minister, Wang Yi, said the key to solving the problem did not lie with his country.

What are the sanctions on North Korea?

UN sanctions include a ban on selling arms and fuel to North Korea, as well as a host of items that could be used for weapons-making.

Also on the list are luxury goods including pearl jewellery and snowmobiles worth $2,000 (£1,540) or more.

Since last year, all cargo entering or leaving North Korea must also be inspected.

But a recent UN study found that fragments from a North Korean missile test included electronics that had been obtained either from or via Chinese enterprises.

The US has separate, stricter sanctions including a blanket ban on trade and a blacklist of anyone dealing with North Korea.