US ‘armada’ said to be on its way to North Korea was in fact thousands of miles away heading in opposite direction.

A US aircraft carrier-led flotilla that the White House said last week was “steaming” towards North Korea to increase pressure on Pyongyang was actually thousands of miles away heading in the opposite direction.

The USS Carl Vinson and three other ships were on Tuesday heading towards North Korea but only after a string of misleading statements about its original course put out last week from the Trump administration.

The confusion about the flotilla’s course threatened to overshadow a visit to Japan by the US vice-president, Mike Pence, intended to demonstrate US resolve over North Korea. Speaking aboard the USS Ronald Reagan at its home port of Yokosuka on Wednesday, Pence pledged to strengthen the US presence in the Asia Pacific region.

“We will defeat any attack and beat any use of conventional or nuclear weapons with an overwhelming and effective American response,” he said.

In Washington, officials are facing questions and criticism over the location and original course of the Vinson flotilla, after it was photographed 3,500 miles away from North Korea, sailing south in the Sunda Strait at a time officials said it was sailing north.

On 11 April, the defence secretary, Jim Mattis, said the Vinson was “on her way up” to the peninsula. White House spokesman Sean Spicer said “when you a see a carrier group steaming into an area like that [it] is clearly a huge deterrence”.

The following day, Donald Trump said: “We are sending an armada. Very powerful.”

Late on Tuesday, the Pentagonsaid the aircraft carrier was finally heading north, after it had sailed south to take part in a preplanned training exercise with the Australian navy. Spokeswoman Dana White told the New York Times: “The ship is now moving north the western Pacific. This should have been communicated more clearly at the time.”

The Carl Vinson and its strike force will not reach the seas off the Korean peninsula until next month.

Joel Wit, a co-founder of the 38 North programme of the US-Korea Institute at Johns Hopkins University, said the confusion was “very perplexing” and fed into North Korea’s narrative that America is all bluster and does not follow through on threats.

“If you are going to threaten the North Koreans, you better make sure your threat is credible,” Wit said. “If you threaten them and your threat is not credible, it’s only going to undermine whatever your policy toward them is.”

The US ratcheted up its rhetoric ahead of North Korea’s military parade and failed missile launch over the weekend.

Kim Jong-un, North Korea’s leader, responded with his own fiery warnings and threatened to conduct weekly missile tests.