North Korea May Be Capable of Sarin-Loaded Missiles, Abe Says

In Tokyo, Pence will deliver remarks aboard the USS Ronald Reagan and will also visit troops in South Korea and Hawaii.

Previously, the North Korean military threatened to unleash a "merciless" response against American targets, including the naval task force the U.S. recently deployed.

North Korea has already conducted five nuclear tests and a series of missile launches.

The North regularly launches short-range missiles, but is also developing mid-range and long-range missiles meant to target US troops in Asia and, eventually, the USA mainland.

Pence's visit is part of a more than weeklong, multi-nation trip to reaffirm USA ties to the region, officials said. The administration's immediate emphasis, the officials said, will be on increasing pressure on Pyongyang with the help of Beijing.

The officials weren't authorized to speak publicly on the results of the policy review and requested anonymity. Military officials are still trying to determine what type of missile it was.

"We're going to consult with the Republic of Korea on North Korea's efforts to advance its ballistic missile and its nuclear program", a White House foreign policy adviser told reporters, previewing Pence's trip.

North Korea's actions come as tensions on the Korean Peninsula have spiked to alarming levels.

He said: " This latest missile test just fits into a pattern of provocative, destabilising, and threatening behaviour on the part of the North Korean regime. "Our military is building and is rapidly becoming stronger than ever before", he tweeted.

Trump tweeted on Tuesday that North Korea was "looking for trouble" and added that if China doesn't do its part to rein in Pyongyang's nuclear ambitions, the US can handle it.

He says "no matter who it is, if it wants to make war or trouble on the Korean Peninsula, it must take the historical responsibility and pay the due price".

"We've seen one - it doesn't prevent him from doing the other". Trump tweeted on Sunday.

Another missile test from Sinpo failed earlier this month, when the rocket spun out of control and plunged into the ocean. She advised patience with China on the issue.

In February, North Korea also simultaneously launched four ballistic missiles off its east coast, three of which landed close to Japan.

Into this tense environment, Pence made his first trip to the region since taking office in January.

The vice president was joined by his wife and two adult daughters and was laying a wreath at the Seoul National Cemetery at the start of his trip. During a fellowship meal after the services, he said the tensions on the Korean peninsula had put into sharp focus the importance of the joint U.S.

"South Korea has some 20 million people within artillery range of North Korea", retired ambassador Chris Hill, the top US envoy to talks with North Korea under President George W. Bush, said on Sunday on ABC's "This Week" program.

Tensions are deepening as the USA has sent an aircraft carrier to waters off the peninsula and is conducting its biggest-ever joint military exercises with South Korea. "So that's why. It's not the DPRK but the USA and Trump that makes trouble".

The attempted launch occurred a day after the regime of Kim Jong Un showed off a bevy of new missiles and launchers at a large-scale military parade. The picture above from 2013 shows leader Kim Jong Un ordering strategic rocket forces to be on standby to strike US and South Korean targets at any time.

It has already conducted five nuclear tests and a series of missile launches in contravention of United Nations resolutions.