South Korea and the United States began joint Navy drills in the waters around the Korean peninsula on Monday (local time), amid high tensions over North Korea's nuclear and missile programs, Reuters reports.
About 40 Navy ships from both countries, including the nuclear-powered USS Ronald Reagan aircraft carrier, are taking part in the week-long exercises on the east and west coasts of the peninsula, said a spokesman for South Korea's defense ministry.
North Korea has criticized the joint military exercises by the United States and South Korea, saying they are a "rehearsal for war".
Last week, the U.S. military flew two Air Force B-1B Lancer bombers over the Korean peninsula in a joint exercise with the South Korean and Japanese militaries.
The drill took place as President Donald Trump met with his national security team to discuss "a range of options" on North Korea in response to its increasing nuclear ambitions.
It came a day after Defense Secretary James Mattis urged military leaders "to be ready" with military options for Trump to deal with North Korea should diplomacy fail.
Tensions on the Korean peninsula have risen sharply in recent weeks following a series of weapons tests by Pyongyang, including its sixth and most powerful nuclear test on September 3 and two missile launches over Japan.
Just last week, North Korea's Foreign Minister, Ri Yong Ho, threatened the United States with “a hail of fire” and said Trump has "lit the wick of war" with his country.
North Korea is preparing to test a long-range missile which it believes can reach the west coast of the United States, according to a Russian lawmaker who returned from a visit to Pyongyang earlier this month.
South Korean intelligence officials and analysts have said that North Korea might time its next provocation to coincide with China's all-important Communist Party Congress which begins on Wednesday.