North Korea fired a sixth short-range missile into the East Sea on Monday, defying warnings from UN chief Ban Ki-moon and South Korea after a flurry of similar tests at the weekend.

The latest firing was confirmed by the South's Joint Chiefs of Staff, who said it was unclear if the North was testing guided missiles or rockets from multiple launchers.

However, North Korea said Monday that the country's missile launches are part of military training for self-defense, the official KCNA news agency reported. In a statement on Monday, Pyongyang angrily rejected criticism that the missile exercises were a deliberate attempt to kick off a fresh cycle of tensions.

The drill, as a powerful deterrent to the US and South Korean attempt for a nuclear war, "is the legitimate right of a sovereign state," the Committee for the Peaceful Unification of Korea said in a statement.

North Korea argues that the real provocation comes from South Korea and the US, which have carried out a series of small and large-scale joint military drills in recent months, involving the participation of nuclear-capable B-2 bombers. 

South Korea labeled the weekend tests "deplorable", while UN chief Ban Ki-moon urged Pyongyang to exercise restraint. "It is time for them to resume dialogue and lower the tensions," Ban said in Moscow on Sunday.

On Monday South Korea's President Park Geun-hye's top security advisor, Kim Jang-soo, again urged Pyongyang to desist from any more drills.

"Whether it's just a test or a show of force, the North should not get involved in actions that create tension," Kim said.

"South Korean military will closely monitor the North Korean military in case of any further launch," Yonhap News Agency said quoting Seoul military official.

"Safeguarding peace and stability on the Korean peninsula is inevitable and the desire of all concerned," said Hong Lei, Chinese Foreign Ministry spokesman at a press briefing Monday. "We hope under the current circumstances all parties will take steps to ease tensions and improve relationships," said Hong, calling for the parties to solve problems through dialogue and negotiation.

North Korea fired three short-range guided missiles off its east coast at the weekend.

Xinhua - Agencies