US troop commitment remains 'ironclad'

US Defense Secretary Jim Mattis yesterday assured South Korea of an "ironclad" commitment to its security, including keeping US troop levels unaltered, even as diplomats seek an agreement with North Korea on denuclearisation.

Mattis, during a brief visit to Seoul, defended US President Donald Trump's decision this month to halt "war games" with South Korea, saying it would increase the opportunity for diplomats to negotiate.

But Mattis added that US and South Korean forces would remain "united, vigilant and ready."

Critics of Trump's decision on the joint military exercises say it is a major concession to North Korea that, if prolonged during what are expected to be lengthy negotiations, risk eroding the readiness of US and South Korean forces.

North Korea has long sought a suspension of the drills.

The decision is part of efforts to defuse tensions and build trust, Mattis and his South Korean counterpart Song Young-moo said in a joint statement after their talks.

"The two ministers agreed to continue exploring confidence and peace-building measures as long as North Korea continues dialogue in good faith," the statement said.

Trump has also drawn criticism from national security analysts for an agreement that emerged from his June 12 summit with North Korean leader Kim Jong Un that had few details on how Pyongyang would surrender its nuclear weapons and ballistic missiles.