AP

SEOUL, South Korea (AP) — North Korea fired a short-range missile into the sea on Friday, Seoul officials said, hours after the U.S., South Korean and Japanese leaders pledged to work closer together to prevent North Korea from advancing its nuclear and missile programs.

The surface-to-air missile fired from an eastern coastal area flew into waters off the North's east coast, South Korea's Joint Chiefs of Staff said in a statement. It gave no further details.

The missile is the latest in a series of weapon launches by the North in an apparent response to ongoing military exercises between the United States and South Korea. North Korea views the drills as an invasion rehearsal.

This year's drills, set to run until late April, are the biggest, and come after North Korea's nuclear test and long-range rocket test earlier this year.

In Washington, President Barack Obama on Thursday met with his South Korean and Japanese counterparts to discusse ways of deterring North Korea's nuclear threats before a two-day nuclear summit that opens Friday. Obama also met Chinese President Xi Jinping and both called for North Korea to give up its nuclear weapons. China also agreed to implement in full the latest economic restrictions imposed by the U.N. Security Council against Pyongyang.

On Tuesday, North Korea fired a short-range projectile that crashed on land in the country's northeast, according to South Korean defense officials. The launch prompted media speculation in South Korea that Pyongyang may have used a land target to test the accuracy of its weapons. In the past, the North has usually fired missiles, artillery shells and rockets into the sea.

Earlier this month, North Korea fired its first medium-launch missile into the sea since early 2014.

Along with missile and artillery launches, North Korea has also repeated threats of nuclear strikes on Seoul and Washington and warned it would tests a nuclear warhead and ballistic missiles capable of carrying it.

Also Friday, South Korea blamed North Korea for sending radio waves to jam GPS signals in South Korea, calling it a provocation. There were no reports of major disruptions in South Korean military, air and naval transport and telecommunication systems.

Media reported that some fishing boats suffered problems in their GPS navigation systems.

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Associated Press writer Kim Tong-hyung contributed to this report.