SEOUL (Reuters) - South Korean President Park Geun Hye said on Wednesday (June 22) that North Korea was heading towards self-destruction with its continued missile and nuclear tests.

"The North Korean regime should realise that complete isolation and self-destruction await at the end of reckless provocation," Ms Park said.

Her remarks come after North Korea launched what appeared to be a second intermediate-range Musudan missile on Wednesday that flew about 400km, more than halfway towards the south-west coast of Japan's main island of Honshu.

Nato Secretary-General Jens Stoltenberg on Wednesday also condemned the launch, and called on the North to stop more "provocative actions".

"I strongly condemn the launch by North Korea of two ballistic missiles," Mr Stoltenberg said in a statement.

"These repeated provocative actions ... undermine international security and dialogue," he said, calling for North Korea to "fully comply with its obligations under international law, not to threaten with or conduct any launches using ballistic missile technology and to refrain from any further provocative actions".

Japanese Defence Minister Nakatani said the second missile reached an altitude of 1,000km, indicating North Korea had made progress.

"We don't know whether it counts as a success, but North Korea has shown some capability with IRBMs (intermediate range ballistic missiles)," he told reporters in Tokyo. "The threat to Japan is intensifying."

Reclusive North Korea and the rich, democratic South are technically still at war because their 1950-1953 conflict ended in an armistice, not a peace treaty.

The North regularly threatens to destroy Japan, South Korea and the South's main ally, the United States.