South Korea's defence ministry said both missiles flew 650 kilometers into the Sea of Japan, upping the ante after a series of short-range missile and rocket launches by the North in recent weeks.

A ministry spokesman said the missiles were believed to be Rodong variants, which are considered medium-range at their maximum reach of between 1,000 and 1,500 kilometers.

UN Security Council resolutions prohibit North Korea from conducting any ballistic missile tests.

Over the past four weeks, North Korea has conducted multiple launches of short-range Scud missiles and rockets to coincide with the annual joint military drills South Korea is conducting with the United States.

The Scuds are at the longer edge of the short-range spectrum, with an estimated reach of 300-800 kilometers -- capable of striking any target in the South.

South Korea condemned the Scud launches as a ‘reckless provocation’ but both Seoul and Washington stopped short of calling for UN sanctions, given the short-range of the missiles and a recent easing of North-South tensions.

The North Korean military had defended the tests as ‘ordinary military practice’.

If the missiles launched on Wednesday are confirmed to be Rodongs, observers said it would lay down a challenge to the international community to consider sanctions.

The last time North Korea was believed to have tested a Rodong missile, also known as Nodong, was in July 2009, following UN condemnation of its second nuclear test in May of the same year.

The latest launches were clearly timed to coincide with the summit in Hague.

The talks between Japanese Prime Minister Shinzo Abe and South Korean President Park Geun-Hye came as Obama sought to help repair strained ties between two of United States closest Asian allies and key partners in the effort to curb North Korea's nuclear programme.

"Over the last five years, close cooperation between the three countries succeeded in changing the game with North Korea," Obama said.

"Our trilateral cooperation has sent a strong signal to Pyongyang that its provocations and threats will be met with a unified response," he added.

Relations between Tokyo and Seoul are at their lowest ebb in years, mired in emotive issues linked to Japan's 1910-45 colonial rule and a territorial dispute, as well as Japan's use of South Korean ‘comfort women’ as sex slaves in wartime brothels.


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