The USS Ronald Reagan aircraft carrier arrives in the South Korean port city of Busan on October 21, 2017.
The military also said another objective of the drills was to "show off the determination for strong retaliation and the firm military readiness", and the ROK and US militaries' ability to "repulse any kind of provocations by North Korea with overwhelming military power in case of contingency".
The US Navy said yesterday that the three vessels - the USS Ronald Reagan, USS Nimitz and USS Theodore Roosevelt - will conduct "coordinated operations in global waters" in the western Pacific between Saturday and Tuesday.
South Korea supports the Belt and Road Initiative and is willing to actively participate in its implementation, he said, while calling for concerted efforts to resume bilateral high-level exchanges and cooperation in various fields as soon as possible.
The US warships will carry out air defense drills, sea surveillance, defensive air combat training and other training operations, the US Navy said.
The exercises come on the heels of US President Donald Trump's visit to Seoul and Beijing this week, with the North's nuclear and missile threats looming large.More news: Syria Signals It Will Sign Paris Climate Deal, Leaving US Alone
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"Multiple carrier strike force operations are very complex, and this exercise in the Western Pacific is a strong testament to the U.S. Pacific Fleet's unique ability and ironclad commitment to the continued security and stability of the region".
Now, a meeting between Chinese president Xi Jinping and his South Korean counterpart Moon Jae-in appears to have strengthened relations between the countries.
Bong Young-shik, an expert on regional relations at South Korea's Yonsei University, said: "China's economic retaliation only pushed Korea closer into the trilateral alliance between Japan and the US".
APEC brings together 21 economies from the Pacific region.
Tensions have been running high since North Korea test-fired two intercontinental ballistic missiles in July, conducted its sixth and most powerful nuclear test on September 3 and flew ballistic missiles over Japan on August 29 and September 15.