The missiles flew about 124 miles, according to the South Korean military.
A USA defense official confirmed a launch had been detected but told CNN the Pentagon was unlikely to release a statement as these were not ballistic missiles capable of posing a long-range threat. Two aircraft carriers-USS Carl Vinson and USS Ronald Reagan-are already in the area, together with their strike groups of destroyers and cruisers, and have been engaged in exercises with Japanese naval vessels. Kim Jong-un has said the country's missile programs are necessary to defend against perceived USA military threats.
"North Korea launched multiple projectiles that appear to be short-range land-to-ship cruise missiles today morning off east coast from the region of Wonsan", the office said in a statement, adding that Seoul and Washington were analyzing the launches for further information.
In the three earlier launches, North Korea tested different kinds of ballistic missiles, two medium-to-long range missiles as well as a short-range Scud class weapon.
"The government is charging at the Thaad deployment and the Korea-US alliance while taking no measures whatsoever against North Korea's missile launches", Chung Woo-taik, floor leader and acting chief of the main opposition Liberty Korea Party, reportedly said.
Local residents' signs calling for the withdrawal of the THAAD missile defense system, near the deployment site in Seongju County, North Gyeongsang Province, June 7.
North Korea fired four anti-ship missiles into the sea east of the Korean Peninsula Thursday, according to US and South Korean military sources.
"The only thing North Korea will earn through provocations is worldwide isolation and economic hardship, and it will lose opportunities for development", Moon said at a meeting of the National Security Council Thursday, according to Blue House spokesman Park Soo-Hyun.
The ask includes $1.5 billion for the $40-billion ground-based midcourse defense system that successfully intercepted and destroyed a mock intercontinental ballistic missile (ICBM) high above the Pacific Ocean last week. While the system's radar had drawn criticism from Chinese officials, delaying its implementation could also hurt Seoul's relationship with US allies, as President Donald Trump has repeatedly sought to portray himself as cracking down on North Korea.
In what will likely become another source of animosities, Moon's government said Thursday that it will let two of the four North Korean fishermen recently rescued at sea resettle in the South in accordance with their wishes.
However China adamantly opposes the THAAD regional deployment that could potentially give the USA the means to counter its missile capabilities as well.
However, South Korea announced last Wednesday that it would suspend further Thaad deployments citing the need for additional evaluation of the environmental and health concerns posed by the system's powerful radar.