Visiting U.S. Vice President Mike Pence described North Korea's failed missile test Sunday as a "provocation" and assured South Korea of Washington's full support against the threat from its volatile neighbor.
President Donald Trump was uncharacteristically quiet about the failed launch of a North Korean missile from the country's east coast.
The extended-range Scud missile in that earlier launch suffered an in-flight failure and fell into the sea off North Korea's east coast, according to USA imagery and assessments.
Former British Foreign Secretary Sir Malcolm Rifkind first suggested to the BBC that the USA could have been behind the failed attempt through an act of sabotage.
"We had good intelligence before the launch and good intelligence after the launch", the adviser told reporters on condition of anonymity.
Sunday's launch was carried out around dawn from Sinpo, a site on North Korea's east coast where it has a shipyard.
Worry about North Korea has also strained ties between China and South Korea because China objects to the deployment of a U.S. Terminal High Altitude Area Defense (THAAD) anti-missile system in the South.
In February 2012, the United States and North Korea announced an agreement in which the North would suspend operations of its Yongbyon uranium enrichment plant, allow worldwide inspectors to verify the suspension, and implement moratoriums on nuclear and long-range missile tests.
Abe, speaking to a parliamentary session Monday following North Korea's massive military parade and botched missile launch, said: "Needless to say, diplomatic effort is important to maintain peace. And our president will take action that is in the best interest of the American people", he said.
"But at the same time, they have made steady progress while we have made agreement after agreement after agreement".
The national security adviser said the latest failed test "fits into a pattern of provocative and destabilizing and threatening behavior on the part of the North Korean regime". "I'm blaming Republican and Democrat presidents over the last 20 years while they continue to make progress".
The North has a habit of test-firing missiles to mark major dates such as Saturday's 105th anniversary of the birth of the nation's founder Kim Il Sung, or as gestures of defiance when top US officials visit the region.
"We need to apply pressure on North Korea so they seriously respond to a dialogue" with the worldwide community, he said, urging China and Russian Federation to play more constructive roles on the issue. deforested stretch of North Korea from a lookout post in the hillside.
Analysts warn that even failed missile launches provide valuable knowledge to North Korea as it tries to build its weapons program. While the North did not conduct a nuclear test, the spectre of a potential test and an escalated US response has trailed Pence as he undertakes his Asian tour. "If they are unable to do so, the US, with its allies, will!" he tweeted Thursday. "Our military is building and is rapidly becoming stronger than ever before", he tweeted.
North Korea's flagship carrier Air Koryo increased its Pyongyang-Beijing flights from twice a week to five times a week after Air China halted its flights to the North. "We will see what happens!"
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. Recent satellite imagery suggests the country could conduct another underground nuclear test at any time. A USA aircraft carrier, the USS Carl Vinson, is heading to waters off Korea in a show of force. The country launched a long-range rocket and conducted two nuclear tests a year ago, including its most powerful to date.