The United States and South Korea on Saturday, Nov. 11, 2017, started joint naval exercises that will involve three USA aircraft carriers in what military officials describe as a clear warning to North Korea.
The upcoming practice is aimed at bolstering the South Korea-U.S. alliance's policy of "extended deterrence" against the North's nuclear and missile provocations, it added.
The battle groups of the USS Ronald Reagan, the Theodore Roosevelt and the Nimitz will successively enter the exercise area during the drills that run until Tuesday, South Korea's Joint Chiefs of Staff said.
The US warships will carry out air defence drills, sea surveillance, defensive air combat training and other training operations, the US Navy said.
China hit the jackpot in three major ways in its recent agreement to mend ties with South Korea over the latter's deployment of a US THAAD antimissile system, according to 38 North, a respected specialist website on North Korea.
The exercise is taking place while U.S. President Donald Trump is on an Asian tour and presenting a united front with regional leaders.
The Chinese president also underscored the importance of South Korea-China relations, saying the conditions on the Korean Peninsula were at a "pivotal" juncture.
Earlier, Chinese President Xi Jinping and President Trump reiterated firm commitment to achieving denuclearisation of the Korean Peninsula and working towards a solution through dialogue and negotiation.
APEC brings together 21 economies from the Pacific region.
"I am very glad to see you again after four months", Moon said at the start of their bilateral summit held on the sidelines of the Asia-Pacific Economic Cooperation Economic Leaders' Meeting here in the Vietnamese city.
The US administration thinks China's economic leverage over North Korea is the key to strong-arming Pyongyang into halting its nuclear weapons and missile programmes.
Beijing fears that squeezing Pyongyang too hard could cause the regime to collapse, sending an influx of refugees across its border and placing the United States army at its doorstep.