North Korean leader Kim Jong Un has delayed a decision on firing missiles towards Guam while he waits to see what the United States does, the North's state media reported on Tuesday as the United States said any dialogue was up to Kim.

The United States and South Korea have prepared for more joint military drills, which has infuriated the North, and experts warned Pyongyang could still go ahead with a provocative plan.

In his first public appearance in about two weeks, Kim inspected the command of the North's army on Monday, examining a plan to fire four missiles aimed at landing near the U.S. Pacific territory of Guam, the official KCNA news agency reported.

"He said that 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 latter will make an important decision as it already declared," KCNA said.

The DPRK stands for North Korea's official name, the Democratic People's Republic of Korea.

In photos released with the KCNA report, Kim was seen holding a baton and pointing at a map showing a flight path for the missiles appearing to start from North Korea's east coast, flying over Japan towards Guam.

North Korea has often threatened to attack the United States and its bases and released similar photos in the past but never followed through.

Pyongyang's latest threat prompted a surge in tensions in the region last week, with U.S. President Donald Trump saying the U.S. military was "locked and loaded" if North Korea acted unwisely.

But U.S. officials have taken a gentler tone in recent days.

Asked by reporters on Tuesday about the North Korean delay, Secretary of State Rex Tillerson said it was up to Kim to decide if he wants to talk to the United States.

“We continue to be interested in finding a way to get to dialogue but that’s up to him,” Tillerson told reporters.

State Department spokeswoman Heather Nauert said North Korea's decision to hold off was not enough and Pyongyang would have to show it was "intent on denuclearising the Korean peninsula."

"I think they would have to do quite a bit more," Nauert said, adding, "They know what they need to do to get us to come to the negotiating table.


PREVENT WAR

South Korean President Moon Jae-in said on Tuesday his government would prevent war by all means.

"Military action on the Korean peninsula can only be decided by South Korea and no one else can decide to take military action without the consent of South Korea," Moon said in a speech to commemorate the anniversary of the nation's liberation from Japanese military rule in 1945.

"The government, putting everything on the line, will block war by all means," Moon said.

The Liberation Day holiday, celebrated by both North and South, will be followed next week by joint U.S.-South Korean military drills.

Asian shares rose for a second day on Tuesday after Kim's comments. The U.S. dollar and Treasury yields climbed after solid U.S. retail data and the easing in U.S.-North Korean rhetoric.

North Korea has continued to develop its nuclear and missile programmes to ward off perceived U.S. hostility, in defiance of U.N. Security Council resolutions and sanctions.

A new study by a London-based think tank and an article in the New York Times that cited it said North Korea had obtained rocket engines probably from a Ukrainian factory via illicit networks.

But U.S. intelligence officials said on Tuesday that North Korea has the ability to produce its own missile engines and intelligence suggests the country does not need to rely on imports.

Japan will seek further reassurance from Washington in meetings between Japan's defence chief and foreign minister and their U.S. counterparts on Thursday.

"The strategic environment is becoming harsher and we need to discuss how we will respond to that," a Japanese foreign ministry official said in a briefing in Tokyo.

"We will look for the U.S. to reaffirm its defence commitment, including the nuclear deterrent."

China, North Korea's main ally and trading partner, has repeatedly urged Pyongyang to halt its weapons programme and at the same time urged South Korea and the United States to stop military drills to lower tensions.

Chinese Foreign Minister Wang Yi, in a telephone conversation with Sigmar Gabriel, Germany's minister for foreign affairs, said tensions on the Korean peninsula were showing some signs of easing but had not passed.

The parties involved should "make a correct judgement and wise choice by taking a responsible attitude towards history and people," Wang said, according to a statement on the Chinese foreign ministry's website.

U.S. Senator Edward Markey, the top Democrat on the Senate Foreign Relations Committee's panel on East Asia, announced on Tuesday he would lead a delegation to Korea, Japan and China,

“The unity of purpose between the United States and our allies in South Korea, Japan, and China is critical in the face of Pyongyang’s increasing nuclear threat,” Markey said in a statement.

Kim Dong-yub, a professor and military expert at Kyungnam University's Institute of Far Eastern Studies in Seoul, urged caution in assuming North Korea was bluffing with its missile threats.

"There is no stepping back for North Korea. Those who don't know the North very well fall into this trap every time (thinking they are easing threats) but we've seen this before."

The United States and South Korea remain technically at war with North Korea after the 1950-53 Korean conflict ended with a truce, not a peace treaty.

North Korea is currently holding three U.S. citizens it accuses of espionage or hostile acts, but now is not the right time to discuss them, KCNA reported, citing a foreign ministry spokesman.

Pyongyang has used detainees to extract concessions, including high-profile visitors from the United States, which has no formal diplomatic relations with North Korea.