WASHINGTON -- US President Donald Trump ratcheted up tensions with North Korea Friday, saying the military is "locked and loaded" to deal with the regime's provocations.

The warning is the latest in an exchange of bellicose rhetoric that has heightened concerns about a possible conflict between Washington and Pyongyang.

"Military solutions are now fully in place, locked and loaded, should North Korea act unwisely," Trump tweeted. "Hopefully Kim Jong Un will find another path!"

Soon after, the president retweeted a US Pacific Command post referring to B-1B Lancer bombers that stand ready on Guam to fulfill the "Fight Tonight" mission of US forces stationed in South Korea. A link also publicized the flight of two such bombers over Korea early this week, the latest show of force against North Korea's threats.

The tit-for-tat war of words began this week after Pyongyang threatened to retaliate against Washington for new United Nations sanctions against the regime. The US orchestrated the unanimous adoption of the resolution in response to the North's two intercontinental ballistic missile tests last month.

Trump warned North Korea Tuesday it will be met with "fire and fury" if it continues to threaten his country. North Korea said it would fire ballistic missiles towards Guam, home to some 7,000 American military personnel.

On Thursday, Trump doubled down on his warnings, saying his "fire and fury" remark may not have been tough enough.

And a day later, he told reporters at his golf club in Bedminster, New Jersey, that his administration is looking at military options "very carefully."

Kim, the North Korean leader, will "truly regret it and he will regret it fast" if he utters an overt threat at Guam or any territory belonging to the US or its allies, he added.

Despite the rhetoric, some Trump administration officials and experts have played down the possibility of an actual conflict breaking out.

US Secretary of State Rex Tillerson told reporters earlier this week that the president was simply speaking in the kind of language Kim would understand to send a strong message that Pyongyang must stop its provocative behavior.

Also this week, the Washington Post reported that US intelligence has determined North Korea is able to miniaturize a nuclear warhead to fit atop one of its missiles.

Pyongyang has long pursued nuclear-tipped ballistic missiles capable of reaching the US mainland in response to what it calls US hostility towards it.

Tensions are expected to spike later this month when South Korea and the US conduct regular military exercises. North Korea calls them a rehearsal for a northward invasion despite the allies' reassurances they are purely defensive.

In a phone call Friday (Seoul time), Chung Eui-yong, the head of South Korea's Presidential National Security Office, and his US counterpart, H.R. McMaster, agreed to discuss in advance any steps they take to respond to Pyongyang, Seoul's presidential office, Cheong Wa Dae, said. (Yonhap)