Mike James and Jane Onyanga-Omara

USA TODAY

South Korean authorities urged their reclusive northern neighbor to stop using “threatening words” Thursday, and called for Pyongyang to enter into dialogue to ease tensions in the region.

The Vatican’s former diplomatic representative to the United Nations also appealed for dialogue, while China urged North Korea and the United States not to "play with fire."

It came as North Korea claimed it was writing an attack plan to fire missiles toward the western Pacific island of Guam — a U.S. territory — "to signal a crucial warning to the U.S.”

The North Korean military is "seriously examining the plan for an enveloping strike at Guam through simultaneous fire of four Hwasong-12 intermediate-range strategic ballistic rockets," North Korea's media reported.

It said the missiles will fly over Japan and land near Guam, located about 2,100 miles southeast of North Korea. The U.S. maintains large naval and air bases on the island.

South Korea’s Yonhap news agency said the plan will not be ready until mid-August.

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“The North's recent threatening words have gone too much and run squarely against with the consensus contained in the statement issued after the (ASEAN Regional Forum). It should stop them immediately," Cho June-hyuck, the spokesman for South Korean’s foreign ministry, told reporters Thursday, according to Yonhap.

"The North should make the right choice and come out to the road toward denuclearization. In particular, (we) urge it again to swiftly respond to our initiative for better inter-Korean relations so as to establish permanent peace on the Korean Peninsula," Cho added.

Archbishop Tomasi, the Vatican’s former diplomatic representative to the U.N., said the “way of conflict is always the wrong way.”

He added that “the way forward is not that of having the latest military technology, but of having an approach of inclusion."

China, Pyongyang's most important ally, called for North Korea and the U.S. to exercise restraint.

"The bottom line on the nuclear issue on the Korean Peninsula is that there must not be any armed conflict there. There is no room for any related party to play with fire on the issue," an editorial on the official Xinhua news agency's website said.

Secretary of State Rex Tillerson and his North Korean counterpart Ri Yong Ho both attended the Association of Southeast Asian Nations (ASEAN) meeting in Manila on Sunday, but avoided any direct contact.

"Expressing grave concern over the escalation of tensions in the Korean Peninsula, the Ministers urged the Democratic People’s Republic of Korea (DPRK) to immediately comply fully with its obligations under all relevant United Nations Security Council Resolutions,” ASEAN’s chairman Alan Peter Cayetano said in a statement Monday.

“They supported initiatives to improve inter-Korean relations towards establishing peace in the Korean Peninsula,” the statement added.

President Trump has promised "fire and fury" on North Korea if it doesn't abandon its nuclear program.

North Korean media said the purpose of the missile launch will be "to interdict the enemy forces on major military bases on Guam and to signal a crucial warning to the U.S."

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Military leaders in North Korea took the opportunity of the world spotlight to make a few digs at Trump. In a statement, North Korean general Kim Rak Gyom, commander of the nation's army, called Trump's "fire and fury" speech "a load of nonsense."

Gyom also called Trump "a guy bereft of reason . . . Only absolute force can work on him."

Among the U.S. military installations on Guam is the sprawling Andersen Air Force Base, as well as Naval Base Guam. The island's positioning in the Pacific is considered a key strategic point for U.S. military planning and presence. At least 6,000 U.S. troops are stationed there.

The island is the USA's most western territory. It is part of the Mariana Islands group, home to U.S. military installations, and it has been the launching point for historic attacks on Asia.

One of Guam's neighbor islands in the Marianas, Tinian Island, was the launching point for the atomic bomb attacks against Hiroshima and Nagasaki in Japan at the end of World War II.