In a clear warning to Kim Jong Un administration at Pyongyang, US and South Korea have started four-day joint naval exercises at South Korea's eastern coast involving three USA aircraft carriers on Saturday.
The two were meeting on the sidelines of the APEC summit of Asia Pacific leaders in the Vietnamese city of Danang.
Signs have been detected that North Korea's military is preparing for winter drills that will begin in December, according to the Joint Chiefs of Staff.
The aircraft carrier USS Ronald Reagan conducts joint drills with the South Korean navy at sea on October 19.
South Korea's military has strengthened vigilance in the wake of the incident and remains prepared for any situation, the JCS said.
The presence of the three aircraft carriers in waters around the Korean Peninsula and the South China Sea, the East China Sea and the Philippine Sea, unnerved North Korea, who said the presence of US strategic assets was the reason for the country needing a nuclear deterrent.
The South Korean military will join a rare U.S. Navy exercise off the coast of the Korean Peninsula this weekend.
Meanwhile, North Korea's foreign ministry spokesperson, on Saturday, said in Pyongyang that Trump's current trip to "our surrounding region" is a warmonger's visit for confrontation to rid the DPRK of its self defensive nuclear deterrence. The Aegis technology refers to missile tracking and guidance.
That includes a stern speech delivered in South Korea's National Assembly on Tuesday, in which he said: 'Do not underestimate us.
The U.S. carriers also participated in separate exercises with three Japanese destroyers on Sunday.
It is the first time three carrier strike groups have operated together in the area since 2007, and comes amid growing tensions on the Korean Peninsula over Pyongyang's nuclear arms and ballistic missile programs.
In recent months, North Korea has tested intercontinental ballistic missiles that could reach the U.S. mainland with further development and has conducted its most powerful nuclear test. Name of the spokesperson was not revealed in state media reports.