Mike Pence has warned that the “era of strategic patience is over” with North Korea and urged China to use its “extraordinary levers” to pressure the regime into abandoning its nuclear and ballistic missile programmes.

Speaking to reporters during a visit to the heavily armed border separating North and South Korea on Monday, the vice-president described Washington’s commitment to South Korea’s security as “unshakeable”, a day after North Korea conducted a failed missile launch, the Guardian reports.

Pence arrived in South Korea amid claims that Sunday’s missile test might have been thwarted by a cyber attack by the US, and warnings from Donald Trump’s chief security adviser that tensions on the Korean peninsula were “coming to a head”.

Pence told US military personnel it was “humbling” to be at the demilitarised zone (DMZ), a four-kilometre-wide strip of land that has come to symbolise the standoff that has defined relations between the North and South since the Korean war ended in an uneasy truce in 1953.

“My father served in the Korean war with the US army, and on the way here we actually saw some of the terrain my father fought alongside Korean forces to help earn your freedom,” he said in an address at Camp Bonifas. “We are grateful to all of those who each and every day stand in the gap for freedom here at the DMZ. It is a testament to the unshakeable bond between our people.”

Pence will offer similar reassurances to Japan – the US’s other main ally in north-east Asia – when he visits Tokyo on Tuesday as part of a 10-day Asia-Pacific tour that includes Indonesia and Australia.

The weekend passed with no sign that North Korea was about to conduct a nuclear test, with the country instead marking the anniversary of the birth of its founder, Kim Il-sung, with a huge military parade that included dozens of missiles, including one experts said could be a new type of intercontinental ballistic missile.

Despite its failure, Sunday’s missile launch was seen as a test of Trump’s resolve after the president warned that he had not ruled out military action against North Korea and sent a US aircraft carrier battle group towards the peninsula.

On Sunday, Trump’s national security adviser, HR McMaster, appeared to confirm the view that the unprecedented show of naval force, which will take US ships to within several hundred kilometres of North Korea’s nuclear test site, was intended to pressure China to do more to rein in its neighbour.

McMaster indicated that Trump was not considering military action at this point, but would continue to work with China to peacefully resolve North Korea’s nuclear and ballistic missile programmes.