SEOUL: North Korea test-fired two medium-range ballistic missiles Wednesday, prompting a stern US reaction after President Barack Obama hosted a landmark Japan-South Korea summit aimed at uniting the three nations against Pyongyang’s nuclear threat.

Washington condemned the tests as “troubling and provocative,” with the US State Department threatening “appropriate measures” for the violation of UN Security Council resolutions prohibiting N. Korea from conducting ballistic missile tests.

S. Korea’s Defense Ministry said both missiles flew 650 kilometers into the Sea of Japan (East Sea), upping the ante after a series of shorter-range launches in recent weeks.

Ministry spokesman Kim Min-Seok identified them as Rodong-class missiles with a maximum range of 1,000-1,500 kilometers.

“This missile is capable of hitting not only most of Japan but also Russia and China,” Kim said, adding they had been fired from mobile launchers near Pyongyang.

N. Korea last tested a Rodong missile in July 2009, following UN condemnation of its second nuclear test in May.

Kim said the tests were clearly timed to coincide with Tuesday’s summit in The Hague between Obama, Japanese Prime Minister Shinzo Abe and S. Korean President Park Geun-Hye.

“The North is boasting its military capability to grab the attention of the international community,” Kim said.

Warning that N. Korea could be building up toward a major provocation, Kim said the South was closely monitoring the situation, but added there were “no signs” of Pyongyang preparing for an imminent nuclear test.

The South’s Foreign Ministry denounced the “wanton violation” of UN resolutions, saying this could only serve to heighten regional tensions.

“We will come up with responses to the provocations in close cooperation with allies, partners and the UN Security Council,” a ministry statement said.

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

S. Korea condemned the Scud launches as a “reckless provocation” but stopped short of calling for UN sanctions, given the short range and a recent easing of North-South tensions.

The trilateral summit in the Netherlands came as Obama sought to help repair strained ties between two of the United States’ closest Asian allies and key partners in the effort to curb N. Korea’s nuclear program.

“Over the last five years, close cooperation between the three countries succeeded in changing the game with N. 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.