Kim Jong-un missile
Kim Jong-un missileReuters

Hours after world leaders discussed the threat from North Korea's nuclear programme at the Nuclear Security Summit, Pyongyang responded by firing a missile into the sea Friday. North Korea fired a projectile off its east coast, and while South Korea's military initially suspected it was a ballistic missile, it later confirmed it was a surface-to-air missile, according to Yonhap news agency. 

On Thursday, U.S. President Barack Obama discussed the North Korea issue with South Korean President Park Geun-hye and Japanese Prime Minister Shinzo Abe on the sidelines of the Nuclear Security Summit 2016 in Washington, and warned the Kim Jong Un-regime of further sanctions. North Korea has already been slapped with its heaviest set of sanctions by the United Nations following its nuclear test in January and a rocket launch in February. 

Obama also brought up the issue during his meeting with Chinese President Xi Jinping. 

"Of great importance to both of us is North Korea's pursuit of nuclear weapons, which threatens the security and stability of the region. President Xi and I are both committed to the denuclearization of the Korean Peninsula," he said, according to the Associated Press

South Korea called the missile firing a "show of defiance" by Pyongyang.

"The North fired off the anti-aircraft missile at around 12:45 p.m. from South Hamgyong Province in the country's northeastern area. The missile was fired toward the East Sea," Yonhap said, citing the Joint Chiefs of Staff.

South Korea also accused the Kim Jong Un regime of using radio waves to jam GPS signals Friday, which it said affected several flights and ships. This is also the latest provocation by the Kim Jong Un-regime, which has protested against the U.S.-South Korea joint military drills that began last month. 

Just earlier this week, North Korea had fired a short-range missile from the Wŏnsan port city in the Kangwŏn Province, which reportedly crashed on land in the country's northeast, sparking speculations of a land target test to check for weapon accuracy. Last week, it had fired several short-range missiles that travelled 200 kilometres before falling into the Sea of Japan.