US President Donald Trump has criticised North Korean leader Kim Jong-un, accusing him of “acting very, very badly”.
Mr Trump made the comments to reporters while departing his Mar-a-Lago resort in Florida, where he spent the weekend.
The US President said administration officials had meetings during the weekend about North Korea, among other issues.
The comment came as the US Secretary of State Rex Tillerson ended his first trip to Asia, which included a meeting with Chinese President Xi Jinping.
On the three-country trip Mr Tillerson also visited Japan and South Korea.
In South Korea, he outlined a tougher strategy to confront North Korea’s nuclear threat.
Earlier in February North Korea test-fired a ballistic missile, which is believed to have splashed down into the sea between the Korean Peninsula and Japan.
When asked about the possibility of using military force to combat the threat from North Korea, Mr Tillerson told a news conference in South Korea’s capital Seoul: “All of the options are on the table”.
Mr Tillerson said the US did not want a military conflict, but if North Korea took actions that threatened South Korean forces or US forces, “that would be met with [an] appropriate response”.
“If they elevate the threat of their weapons program to a level that we believe requires action, that option is on the table,” he said.
But Mr Tillerson said that by taking other steps, including sanctions, the US was hopeful that North Korea could be persuaded to take a different course before it reached that point.
Past US administrations have considered military force against North Korea over its development of nuclear weapons and ballistic missiles, but rarely has that option been expressed so explicitly.
North Korea has accelerated its weapons development, violating multiple UN Security Council resolutions and appearing undeterred by tough international sanctions.
Mr Trump criticised North Korea on Twitter at the end of last week, writing that the country “has been ‘playing’ the United States for years”.
He also criticised China of doing “little to help”.