The US aircraft carrier USS Carl Vinson on Saturday kicked off a joint drill with the South Korean navy, officials said, as tensions rose over North Korea's latest test-fire of a ballistic missile.
"Immediately after the aircraft carrier arrived in the Sea of Japan, South Korea and the US strike forces launched a drill from 6:00 pm (0900 GMT) Saturday", a defence ministry spokesman told AFP.
The drill came hours after the North launched a ballistic missile in apparent defiance of a concerted US push for tougher international sanctions to curb Pyongyang's nuclear weapons ambitions.
The drill aimed to verify the allies' capability to track and intercept enemy ballistic missiles, the spokesman said.
He declined to clarify how long the drill would last, but Yonhap news agency said it was expected to continue until sometime next week.
The drill will also include a live-fire exercise and anti-submarine maneouvres, the spokesman added.
It would mark the USS Carl Vinson's second operation in South Korean waters in less than two months amid heightened military tensions in Korea. In March, the aircraft carrier carried out annual joint drills.
Earlier this week, the US carrier had joint drills with Japan's naval forces.
North Korea's state media has said the North's military is capable of sinking the aircraft carrier with a single strike.
The latest missile launch, which South Korea said was a failure, came after US Secretary of State Rex Tillerson warned the UN Security Council of "catastrophic consequences" if the international community -- most notably China -- failed to pressure the North into abandoning its weapons programme.
Military options for dealing with the North were still "on the table", Tillerson warned in his first address to the UN body.
The launch ratchets up tensions on the Korean peninsula, with Washington and Pyongyang locked in an ever-tighter spiral of threat, counter-threat and escalating military preparedness.
US President Donald Trump, who has warned of a "major conflict" with North Korean leader Kim Jong-Un's regime, said the latest test was a pointed snub to China -- the North's main ally and economic lifeline.
"North Korea disrespected the wishes of China & its highly respected President when it launched, though unsuccessfully, a missile today. Bad!" Trump tweeted.