North Korea's nuclear test site is ready for at least three more blasts at any time, and the communist nation could conduct one to mark next month's anniversary of its first nuclear test, a US expert said Tuesday.

Joel Wit, chief editor of the website 38 North, made the remark in an op-ed piece in the New York Times, stressing that the next US administration should launch a new diplomatic initiative to curb Pyongyang's dangerously accelerating nuclear and missile programs.

"Satellite photos of North Korea's nuclear test site indicate that at least three more tests are possible at a moment's notice,"

Wit said. "Since North Koreans often celebrate important dates with spectacular shows, the approaching 10th anniversary of its first nuclear detonation on Oct. 9 might be the perfect occasion."

The North's fifth nuclear test last week and a series of missile launches in recent months show that Pyongyang may be able to deploy more powerful nuclear weapons and more dangerous delivery systems more quickly than previously expected, Wit said.

"Last year, researchers at the institute where I work concluded that by 2020 North Korea could field an intercontinental ballistic missile able to reach the United States. But if Pyongyang tests the missile that has appeared in recent military parades, it could be sooner," he said.

"The simple hydrogen bomb the North Koreans were expected to have by 2020 now may be ready and mounted on a missile earlier," he added.

Wit, a former State Department negotiator with North Korea, said that the latest developments should "put to rest the misconceptions that have driven the United States' failed North Korea policy, especially the idea that China, Pyongyang's closest ally, will solve the problem."

"Beijing would certainly prefer that Kim Jong-un give up his nuclear weapons. And the Chinese do occasionally use their economic ties with North Korea to pressure Pyongyang. But China's overriding priority will continue to be keeping North Korea as a stable buffer against American influence in South Korea," Wit said. 

"No amount of cajoling from Washington will cause China to squeeze North Korea with enough sanctions that it will give up its weapons or risk the government's collapse," he said. "The next administration must recognize that the United States, not China, is the indispensable nation when it comes to dealing with North Korea."

Wit also said the new administration should take all necessary measures to protect allies, even if it means angering China, such as the deployment of the THAAD missile defense system. It also should tighten sanctions while recognizing that sanctions won't have the same effect they had no Iran, he said.

"A successful strategy will have to include a new diplomatic initiative aimed at persuading the North to first stop expanding its arsenal and then to eventually reduce and dismantle its weapons," Wit said.

Addressing the North's security concerns is a key element in persuading the North, he said. 

Temporarily suspending or modifying US-South Korea joint military exercises, which the North have denounced as preparations for invasion, could be one of the short-term measures to address Pyongyang's security concerns, he said, adding that long-term measures include replacing the Korean War armistice with a permanent peace agreement.

Economic reasons may motivate the North to consider denuclearization, Wit said.

"As the Obama administration winds down, little can be done to change policy at this point. Moreover, the North Koreans are unlikely to be responsive to new initiatives since they know that the next American administration will have its own approach," Wit said. 

"The first hundred days in office will be critical for the next American president. If a window is open to curb North Korea's nuclear ambitions, it may not stay open for long," he said. (Yonhap)