U.S. President Donald Trump further escalated the war of words with North Korea on Friday, saying the U.S. military is "locked and loaded" for action.

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

Speaking to reporters at his golf club in New Jersey following a meeting of security officials, Trump said he will talk with Chinese President Xi Jinping on the phone later in the day, apparently to discuss the tensions arising from North Korea's planned ballistic missile launch toward Guam.

"I will be speaking to President Xi tonight, from China. And we've been working very closely with China and with other countries," Trump said.

Trump made the remarks after North Korea's official Korean Central News Agency put out a statement accusing him of stoking tensions on the Korean Peninsula.

"Trump is driving the situation on the Korean peninsula to the brink of a nuclear war, making such outcries as 'the U.S. will not rule out a war against the DPRK'," KCNA said. DPRK is the acronym for the Democratic People's Republic of Korea, the country's official name.

Pyongyang has said it will develop a plan by mid-August to launch four missiles near the U.S. Pacific territory of Guam, home to about 7,000 troops and 160,000 people.

Japan is currently deploying Patriot Advanced Capability-3 surface-to-air interceptors along the possible path North Korean ballistic missiles launched toward Guam would take.

The missile defense system is being deployed in the western prefectures of Shimane, Hiroshima and Kochi, which North Korea said its missiles could cross over, as well as Ehime.

Trump expressed hope later in the day that North Korea sufficiently understands what he said about the U.S. military being "locked and loaded" in response to threats from the country.

"We are looking at that very carefully and I hope they are going to fully understand the gravity of what I said, and what I said is what I mean," he told reporters at the golf club. "Those words are very, very easy to understand."

"If he does anything with respect to Guam or any place else that's an American territory or an American ally, he will truly regret it. And he will regret it fast," Trump said, referring to the North Korean leader.

Also Friday, the Associated Press reported that the United States has been engaged in back-channel diplomacy with North Korea for several months, involving Joseph Yun, the U.S. envoy for North Korea policy, and Pak Song Il, a senior North Korean diplomat at the country's U.N. mission.

It had been known that the two sides had discussions to secure the June release of an American university student held in North Korea. But it wasn't known until now that the contacts have continued, or that they have broached matters other than U.S. detainees, the AP said.

Tensions between Washington and Pyongyang have escalated since North Korea tested two intercontinental ballistic missiles in July.

Last Saturday, the U.N. Security Council imposed fresh sanctions on Pyongyang that aim to slash the country's $3 billion annual export revenue by a third.

At the annual security meeting of Asia-Pacific foreign ministers in the Philippines on Monday, North Korea's Foreign Minister Ri Yong Ho defended his country's nuclear and missile programs as legitimate and self-defensive in nature.

The Washington Post reported Tuesday that North Korea has successfully produced a miniaturized nuclear warhead that can fit inside missiles, citing a confidential U.S. assessment.