A day after North Korea said it would regularly test missiles, the US military is considering shooting down the missile tests to pressure the country into denuclearisation.
According to a report in Guardian on Tuesday, the US is exploring ways short of war to pressure the country into denuclearisation, particularly if Pyongyang goes forward with a sixth nuclear test.
The military has not decided to intercept a test missile but the US defense secretary James Mattis has briefed Congress on the option.
Earlier, US vice-president Mike Pence warned North Korea against testing Trump's "resolve", and said that former US President Barack Obama's "strategic patience" policy had ended.
North Korea will continue to test missiles on a weekly, monthly and yearly basis, Vice Foreign Minister Han Song-ryol said.
He said that an "all-out war" would result if the US took military action.
Former US officials speculate that the shoot-down strategy would risk an escalation that Washington might not be able to control.
"I would see such an action as escalatory, but I couldn't guess how Kim Jong-un would interpret it," the report quoted Abraham Denmark, a senior official in Barack Obama's administration, as saying.
"But I would be concerned he would feel the need to react strongly, as he would not want to appear weak," Denmark added.
According to the report, the military might attempt a missile shoot-down with an Aegis missile-defense system aboard a US navy destroyer.
There are also chances that US might convince Japan to use its own missile-defense capabilities against a ballistic missile test traversing Japanese waters.
"The USS Carl Vinson carrier strike group, which includes Aegis-equipped destroyers, is headed for the Korean peninsula," the report noted.
But officials at Pentagon are believed to be unsure how North Korea would respond if US the shoots down a test missile.
"We are exploring a new range of diplomatic, security, and economic measures and all options are on the table," Gary Ross, a Pentagon spokesman, said.
The probability of Aegis interceptors missing a North Korean target would be embarrassing for the US and embolden Pyongyang.
US officials believe that this factor also complicates the shoot-down strategy.
According to Patrick Cronin, senior director of the Asia-Pacific Security Programme at the Centre for a New American Security, the failure to bring down a missile would give North Korea a "psychological advantage".
North Korea has accelerated its nuclear and missile tests in recent years, despite international condemnation and UN sanctions.
Its aim is to be able to put a nuclear warhead on an intercontinental ballistic missile that can reach targets around the world, including the US.
US President Donald Trump has said that will not happen, and stepped up pressure on the isolated North.
Despite the tension, North Korea may carry out a sixth nuclear test soon, observers say. It test-fired a missile on Sunday that exploded within seconds of launch, following a grand military parade on Saturday.