The statement was made amid escalation of tensions on the Korean peninsula with South Korean and United States military having reported on April 16, that they had registered what they believed to be a failed missile test by Pyongyang.
"We appreciate the challenging time in which the people of Japan live with increasing provocation across the Sea of Japan", Pence said in Tokyo before a lunch with Japanese Prime Minister Shinzo Abe.
"If we notice any sign of assault on our sovereignty, our army will launch merciless military strikes against the USA aggressors, wherever they may exist, from the remote United States lands to the American military bases on the Korean Peninsula, such as those of Japan and elsewhere", Ryol said.
He added that "we need to apply pressure on North Korea, so they seriously respond to a dialogue" with the worldwide community, urging China and Russian Federation to play more constructive roles on the issue.
The vice president also said the US would promote peaceful dialogue and defend human rights, "because the dignity and worth of every person is an eternal value of the United States".
'We'll be conducting more missile tests on a weekly, monthly and yearly basis, ' Vice Foreign Minister Han Song-Ryol said in an interview with the BBC.
Abe said that it was a "matter of paramount importance for us to seek diplomatic efforts as well peaceable settlements of the issue". "The TPP is a thing of the past for the United States of America".
That was followed by more threats to launch missiles and maybe even a nuclear one against the United States.
He said Trump's "strength and resolve" had been evident for the world to see in recent weeks, citing the cruise missile strike on a Syrian regime airbase and the dropping of a Massive Ordnance Air Blast bomb on an ISIS location in Afghanistan.
The Trump administration has said military action remains an option for dealing with North Korea. In the middle of him talking with North Korea I'm going to hit them with currency manipulation?
Suga, the Japanese government spokesman, said Japan hopes to discuss policies on North Korea with Pence and to convey a growing sense of urgency over its missile tests and other actions. "Nobody's ever seen such a positive response on our behalf from China", Trump said.
An "all-out war" would be the result of the continuing military tensions with the USA and warned North America about being "reckless enough to use military means". Pence stood a few metres from the military demarcation line outside Freedom House, gazing at the North Korean soldiers across the border, and then peered at a deforested stretch of North Korea from a lookout post in the hillside.
Pence's economic discussions in Tokyo will be closely watched to see how hard a line Washington is prepared to take on trade.
While Japan's trade surplus with the U.S.is much smaller than China's, Trump has decried the imbalance, especially in auto exports.
Earlier in the trip, the vice president said he hopes the tensions with North Korea can be resolved peacefully, but underscored that President Trump will not tolerate any more shenanigans from saber-rattling Kim Jong-Un.
BEIJING (AP) - China defended its trade practices on Tuesday after Chinese-made vehicles were seen towing ballistic missiles during a North Korea military parade despite global sanctions against selling military hardware to Pyongyang.