By Jonathan Cheng, Wall Street Journal–

North Korean leader Kim Jong Un has decided not to launch a threatened missile attack on Guam, Pyongyang’s state media reported on Tuesday, but warned that he could change his mind “if the Yankees persist in their extremely dangerous reckless actions.”

(For a deeper analysis of the issues in this story, please see “North Korea Backs Off Threat to Hit Guam”)

The report, published early Tuesday, could help dial back tensions that had spiraled last week following an exchange of threats between North Korea and U.S. President Donald Trump.

Mr. Trump warned Pyongyang last week that the U.S. military was “locked and loaded” and could engulf the North in “fire and fury,” while North Korea, through its state media, had threatened to fire four missiles in a bid to surround the U.S. territory of Guam in “enveloping fire.”

North Korean state media said in its report Tuesday that Mr. Kim had made his decision not to fire on Guam after visiting a military command post and examining a military plan presented to him by his senior officers.

While Mr. Kim said he had decided not to launch the attack on Guam yet, he advised the U.S. “to take into full account” whether the current standoff was to its benefit. He also said it was incumbent on the U.S. to “stop at once arrogant provocations against the DPRK and unilateral demands and not provoke it any longer,” using an abbreviation for the Democratic People’s Republic of Korea, the formal name for North Korea.

“If the Yankees persist in their extremely dangerous reckless actions on the Korean Peninsula and in its vicinity, testing the self-restraint of the DPRK, the

[North] will make an important decision as it already declared,” the report quoted Mr. Kim as saying.

In Guam, authorities welcomed the apparent lifting of the missile threat from North Korean leader Kim Jong Un.

“We are happy that the rhetoric has calmed down, that he won’t be pursuing his threats to fire missiles at Guam,” said Lt. Gov. Ray Tenorio. “The comments allay some of the concerns and the fears.”

The U.S. military on Guam would maintain a high level of readiness to respond to any threat, said Greg Kuntz, deputy public affairs officer for Joint Region Marianas.

Guam is home to two major U.S. military bases. The island is situated roughly 3,800 miles west of Hawaii and 2,100 miles south-southeast of Pyongyang.

—Lucy Craymer contributed to this article.

Write to Jonathan Cheng at jonathan.cheng@wsj.com