'Impossible to overstate danger posed by North Korean regime'
US president Donald Trump's national security adviser HR McMaster has stressed that it is "impossible to overstate the danger" posed by North Korea.
In an interview with MSNBC's Hugh Hewitt, Mr McMaster said Mr Trump has been "deeply briefed" on the strategy on North Korea.
Tensions have mounted with Pyongyang's two recent successful tests of intercontinental ballistic missiles.
Mr McMaster reiterated the administration's position that all options, including a targeted military strike, are on the table.
Still, he acknowledged this "would be a very costly war, in terms of ... the suffering of mainly the South Korean people."
McMaster continued: "So what we have to do is .... everything we can to pressure this regime, to pressure Kim Jong Un and those around him such that they conclude it is in their interest to denuclearise."
The comments came as US secretary of state Rex Tillerson arrived in the Philippines for a regional summit expected to focus heavily on concerns with North Korea.
Mr Tillerson has no plans to sit down with North Korean foreign minister Ri Yong Ho at the event.
Mr Tillerson's reluctance to meet his North Korean counterpart is despite his growing push for Pyongyang to return to the negotiating table with the US.
The US secretary of state said this week that such talks would have to be predicated on the North giving up its nuclear weapons aspirations and that the conditions for such talks have not yet been met by North Korea's government.
The UN Security Council has unanimously approved new sanctions on North Korea, including banning exports worth over one billion dollars.