US, South Korea begin largest-ever joint air drill     

SEOUL – Agence France-Presse

The U.S. and South Korea on Dec. 4 kicked off their largest ever joint air exercise, an operation North Korea has labelled an "all-out provocation," days after Pyongyang fired its most powerful intercontinental ballistic missile.

The five-day Vigilant Ace drill -- involving 230 aircraft, including F-22 Raptor stealth jet fighters, and tens of thousands of troops -- began Monday morning, Seoul's air force said.

Pyongyang over the weekend blasted the drill, accusing U.S. President Donald's Trump's administration of "begging for nuclear war."

The annual exercise comes five days after the nuclear-armed North test-fired a new ICBM, which it says brings the whole of the continental United States within range.

As tensions surged, U.S. Senator Lindsey Graham, an influential Republican and foreign policy hawk, warned that the U.S. was moving closer to "preemptive war" with the North.             

"If there's an underground nuclear test (by the North), then you need to get ready for a very serious response by the United States," Graham told the CBS show "Face the Nation."

The isolated and impoverished North has staged six increasingly powerful atomic tests since 2006 -- most recently in September.

In recent years Pyongyang has accelerated its drive to bring together nuclear and missile technology capable of threatening the U.S., which it accuses of hostility.

"The preemption is becoming more likely as their technology matures. Every missile test, every underground test of a nuclear weapon, means the marriage is more likely," Graham said.     

His remarks echoed those of Trump's National Security Adviser HR McMaster, who told a security forum on Saturday that the potential for war with the North "is increasing every day."      

This year's U.S. and South Korean wargames feature a number of powerful jet fighters newly mobilised for the event, including six F-22s and 18 units of F-35 combat jets, the U.S. air force said.

It also involves simulated precision attacks on the North's military installations, including its missile launch sites and artillery units, Yonhap news agency said, citing unnamed Seoul sources.