North Korea says it's ready to strike U.S. aircraft carrier

North Korea said on Sunday itwas ready to sink a U.S. aircraft carrier to demonstrate itsmilitary might, as two Japanese navy ships joined a U.S. carriergroup for exercises in the western Pacific.

U.S. President Donald Trump ordered the USS Carl Vinsoncarrier strike group to sail to waters off the Korean peninsulain response to rising tension over the North's nuclear andmissile tests, and its threats to attack the United States andits Asian allies.

The United States has not specified where the carrier strikegroup is as it approaches the area. U.S. Vice President MikePence said on Saturday it would arrive "within days" but gave noother details.

North Korea has responded with a warning.

"Our revolutionary forces are combat-ready to sink a U.S.nuclear-powered aircraft carrier with a single strike," theRodong Sinmun, the newspaper of the North's ruling Workers'Party, said in a commentary.

• CBC IN NORTH KOREA |Why Pyongyang is using gleaming skyscrapers to show 'potential of socialist Korea'

The paper likened the aircraft carrier to a "gross animal"and said a strike on it would be "an actual example to show ourmilitary's force."

The commentary was carried on page three of the newspaper,after a two-page feature about leader Kim Jong-un inspecting apig farm.

Speaking during a visit to Greece, Chinese Foreign MinisterWang Yi said there were already enough shows of force andconfrontation at present and appealed for calm.

"We need to issue peaceful and rational sounds," Wang said,according to a statement issued by China's foreign ministry.

N. Korea detains U.S.citizen

Adding to the tensions, North Korea detained aKorean-American man in his fifties on Friday, South Korea'sYonhap news agency reported, bringing the total number of U.S.citizens held by Pyongyang to three.

Tony Kim, who also goes by his Korean name Kim Sang-duk, taught accounting for about a month at the Pyongyang University of Science and Technology, according to its chancellor Park Chan-mo.

Park said Kim was detained by officials as he was trying to leave the country from Pyongyang's international airport.

• CBC's Saa Petricic on what it's like reporting from North Korea
• Hyeon Soo Lim, Toronto pastor, sentenced to life in prison in North Korea

The Swedish Embassy in Pyongyang said it was aware of a Korean-American citizen being detained recently, but could not comment further.

The embassy looks after consular affairs for the United States in North Korea because the two countries do not have diplomatic relations.

North Korea will mark the 85th anniversary of the foundationof its Korean People's Army on Tuesday.

• N. Korea displays new type of ballistic missile at military parade, S. Korea says
• North Korea warns of nuclear attack on U.S. at any sign of aggression

It has in the past marked important anniversaries with testsof its weapons.

North Korea has conducted five nuclear tests, two of themlast year, and is working to develop nuclear-tipped missilesthat can reach the United States.

It has also carried out a series of ballistic missile testsin defiance of United Nations sanctions.

North Korea's growing nuclear and missile threat is perhapsthe most serious security challenge confronting Trump.

He has vowed to prevent the North from being able to hit theUnited States with a nuclear missile and has said all optionsare on the table, including a military strike.

Worry in Japan

North Korea says its nuclear programis for self-defenceand has warned the United States of a nuclear attack in responseto any aggression. It has also threatened to lay waste to South
Korea and Japan.

U.S. DefenceSecretary Jim Mattis said on Friday NorthKorea's recent statements were provocative but had proven to behollow in the past and should not be trusted.

• No winners if war with North Korea breaks out, warns China

"We've all come to hear their words repeatedly; their wordhas not proven honest," Mattis told a news conference in TelAviv, before the latest threat to the aircraft carrier.

Japan's show of naval force reflects growing concern thatNorth Korea could strike it with nuclear or chemical warheads.

Some Japanese ruling party legislatorsare urging PrimeMinister Shinzo Abe to acquire strike weapons that could hitNorth Korean missile forces before any imminent attack.

Japan's navy, which is mostly a destroyer fleet, is thesecond largest in Asia after China's.

On patrol east of Philippines

The two Japanese warships, the Samidare and Ashigara, leftwestern Japan on Friday to join the Carl Vinson and will"practice a variety of tactics" with the U.S. strike group, theJapan Maritime Self Defence Force said in a statement.

• U.S. ready to stand alone against North Korea, Trump says
• U.S. Secretary of State says policy of 'strategic patience' with North Korea over

The Japanese force did not specify where the exercises weretaking place, but by Sunday the destroyers could have reached anarea 2,500 kilometressouth of Japan, which would be eastof the Philippines.

From there, it could take three days to reach waters off theKorean peninsula. Japan's ships would accompany the Carl Vinsonnorth at least into the East China Sea, a source with knowledgeof the plan said.

U.S. and South Korean officials have been saying for weeksthat the North could soon stage another nuclear test, somethingthe United States, China and others have warned against.

South Korea has put its forces on heightened alert.

China, North Korea's sole major ally, opposes Pyongyang'sweapons programmes and has appealed for calm. The United Stateshas called on China to do more to help defuse the tension.

Last Thursday, Trump praised Chinese efforts to rein in "themenace of North Korea", after North Korean state media warnedthe United States of a "super-mighty pre-emptive strike."