south korea

An American THAAD missile defense system is now operational in South Korea, less than two months after its components arrived there, the U.S. military says.

The system is meant to protect South Korea from ballistic missiles fired by North Korea, the Pentagon says. But China and other critics of the move say it will only increase tensions on the Korean Peninsula. The decision to install the missile shield was made by the U.S. and South Korea last July.

President Trump says that while he would like to resolve the issue of North Korea's nuclear program diplomatically, it will be hard — and there is a potential for a major clash with the Asian nation, Trump said in an interview with Reuters.

"There's a chance that we could end up having a major, major conflict with North Korea, absolutely," the president told the news agency. "We'd love to solve things diplomatically but it's very difficult."

A U.S. Navy strike group has been ordered to relocate to the western Pacific Ocean, providing a physical presence near the Korean Peninsula as concerns mount over North Korea's missile program.

The Pentagon announced the deployment late Saturday. In a statement, U.S. Pacific Command spokesman David Benham said the Carl Vinson Strike Group set sail toward the peninsula from Singapore.

Updated at 5:10 p.m. ET

Secretary of State Rex Tillerson says the U.S. doesn't want to take military action against North Korea, but "all of the options are on the table" if a serious threat arises. Tillerson made his frank remarks in a visit to South Korea on Friday, a day after saying diplomatic efforts "have failed" to persuade North Korea to abandon its nuclear program.

Tillerson's Asia tour began in Japan and will end in China. The top American diplomat is traveling without a press contingent.