Visitors watch a photo showing North Korea's missile launch at the Unification Observation Post in Paju, South Korea, near the…
Visitors watch a photo showing North Korea's missile launch at the Unification Observation Post in Paju, South Korea, near the border with North Korea, Dec. 13, 2019.

WASHINGTON - As Pyongyang appears to be preparing to launch a long-range missile, experts see an end to a diplomatic process Washington has pursued to denuclearize North Korea.

"I see no signs that the North Koreans are interested in talking to the U.S. at this time," said Joshua Pollack, a North Korean expert at the Middlebury Institute of International Studies in California. "They appear to have made their decision."

On Tuesday, a top U.S. Air Force general said he is expecting North Korea to launch a long-range ballistic missile as a "Christmas gift" to the U.S.

"What I would expect is some type of long-range ballistic missile would be the gift," said Gen. Charles Brown, commander of Pacific Air Forces and air component commander for U.S. Indo-Pacific Command.

"It's just a matter of does it come on Christmas Eve? Does it come on Christmas Day? Does it come after the New Year?"  

Earlier this month, North Korea said, "It is entirely up to the U.S. what Christmas gift it will select to get."

The statement came as Pyongyang issued a series of warnings demanding that Washington change its stance on denuclearization talks by the end-of-the-year deadline Pyongyang unilaterally imposed on Washington.

FILE - U.S. President Donald Trump shakes hands with North Korean leader Kim Jong Un as they meet at the demilitarized zone separating the two Koreas, in Panmunjom, South Korea, June 30, 2019.

Washington and Pyongyang have been locked in their respective positions since talks failed at the Hanoi Summit held in February. There, North Korean leader Kim Jong Un asked U.S. President Donald Trump for sanctions relief. Trump denied the request and asked instead for full denuclearization before granting any relaxation of sanctions.

North Korea has increased provocations by conducting 13 rounds of missile tests since May in an effort to pressure the U.S. to grant sanctions relief.

This month, North Korea conducted two tests within a week that experts think may be related to preparations for launching an intercontinental ballistic missile (ICBM).  

North Korea said it conducted a "crucial test" on Friday at its Sohae Satellite Launching Ground, the site of its long-range missile launch, to "bolster up the reliable strategic nuclear deterrent" against U.S. threats.   

The test comes after another "very important test" North Korea said it carried out on Dec. 7 at the same launching site.  

Experts think North Korea will continue to increase threats that could put an end to diplomacy.

"Pyongyang is expected to move up the escalation ladder in attempts to induce U.S. concessions," said Bruce Klingner, former CIA deputy division chief of Korea and current senior research fellow at the Heritage Foundation. "The regime could incrementally raise tensions with medium- and intermediate-range missile launches or jump to an ICBM or nuclear test."

Evans Revere, a former State Department official who had negotiated with North Korea extensively, said, "A major military provocation, nuclear test or ICBM launch could well bring the diplomatic process to an abrupt end."  

People watch a TV screen showing a file image of a ground test of North Korea's rocket engine during a news program at the Seoul Railway Station in Seoul, South Korea, Dec. 9, 2019.

If North Korea conducts an ICBM or nuclear weapons test, experts think the U.S. is likely to respond with threats to use force rather than cave in to Pyongyang's pressure, according to experts.

"There are concerns that Trump could either return to threats of preventive attacks, which could lead to an all-out war on the peninsula, or accept a minimal, poorly crafted deal to maintain the façade of progress with Kim Jong Un," said Klingner.

Gary Samore, a former White House coordinator for arms control and weapons of mass destruction in the Obama administration, said, "A full long-range missile test is a little dangerous for Kim Jong Un because Trump may overreach and start threatening military actions."  

Earlier in December, Trump threatened to use force against North Korea if necessary.  He said, "We have the most powerful military we've ever had."  He continued, "And hopefully, we don't have to use it. But if we do, we'll use it. If we have to, we'll do it."

In response, North Korea's army chief of staff Pak Jong Chon said, "The use of armed force is not the privilege of the U.S. only.  

While tensions are expected to continue heightening, experts said the only way forward on denuclearization talks is for either Washington or Pyongyang to change position.

"Unless the U.S. or North Korea change their position, there's no progress on denuclearization," said Samore.  

Ken Gause, director of the adversary analytics program at CNA, said, "Unless the U.S. puts concessions on the table, it is unlikely that North Korea will come to the negotiating table."

However, a State Department spokesperson told VOA's Korean Service on Monday the U.N. must maintain sanctions currently in place on North Korea.

"Now is not the time for the U.N. Security Council to consider offering premature sanctions relief," said the spokesperson. "The DPRK is threatening to conduct an escalated provocation, refusing to meet to discuss denuclearization and continuing to maintain and advance its prohibited weapons of mass destruction and ballistic missile program."

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

The statement was made in response to a Chinese and Russian proposal made on Monday for the U.N. Security Council to lift sanctions placed on North Korea's major export commodities including coal, iron, seafood and textiles, and to ease restrictions on North Koreans working overseas whose remittance provide the Kim regime with much needed hard currency. 

The U.N. Security Council ramped up sanctions on North Korea in 2016 in an effort to make the country give up its nuclear weapons program.

Ham Ji-ha contributed to this report.