Thomas Maresca

Special to USA TODAY

SEOUL — Researchers have discovered another secret ballistic missile base in North Korea, one of an estimated 20 that the communist state has not declared.

The base, called Sino-ri, was disclosed in a report released Monday by the Center for Strategic and International Studies (CSIS), a Washington D.C.-based think tank.

It is located 132 miles north of the demilitarized zone that divides North and South Korea and provides “an operational-level nuclear or conventional first strike capability against targets located both throughout the Korean Peninsula and in most of Japan,” according to the report.

CSIS reported on the existence of 13 of the 20 undeclared missile bases in November. The newly identified Sino-ri facility is one of the oldest in existence and was used for the first deployments of Pyongyang’s Scud missiles and its Nodong medium-range ballistic missile, according to Monday’s report.

The base may also have also played a role in the development of the Pukkuksong-2 (KN-15) medium range ballistic missile, which was first tested in February 2017 and is capable of carrying a nuclear warhead.

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The report comes after just days after the White House announcement that a second summit is going to be held between President Donald Trump and North Korean leader Kim Jong Un in late February.

Trump on Saturday told reporters that “things are going very well with North Korea,” and that Washington and Pyongyang “have made a lot of progress as far as denuclearization is concerned.”

The summit is expected to be held in Vietnam, according to several media reports, with both the capital Hanoi and the coastal city of Danang being touted as possible host sites.

Trump has tended to downplay the threat from North Korea in tweets and statements dating back to his initial summit with Kim last June in Singapore. After that meeting, Trump tweeted that that “everybody can now feel much safer” and that "There is no longer a Nuclear Threat from North Korea."

A Pentagon report released on Thursday, however, said that North Korea’s missile and nuclear program remained an “extraordinary threat” to the United States and warned that the U.S. must remain “remain vigilant” despite ongoing diplomatic engagement with the North.

The CSIS report further suggests North Korea has done little to curtail its nuclear and missile programs despite gestures such as decommissioning its Sohae satellite launch facility in July and August.

That move gained media attention but it “obscures the military threat to U.S. forces and South Korea from [Sino-ri] and other undeclared ballistic missile bases,” the report said.

North Korea also made a show of dismantling its Punggye-ri nuclear test site in May, although international inspectors have not been allowed to visit the site.

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The first Trump-Kim summit produced a vaguely worded declaration that North Korea would work toward a “complete denuclearization of the Korean peninsula.” However, the U.S. and North Korea have been at an impasse over how to proceed and the second summit will seek to find a way forward.

Pyongyang has been looking for concessions such as relief of punishing international sanctions in exchange for steps it has already taken while Washington has been holding out for complete denuclearization first.

South Korean foreign minister Kang Kyung-wha said last week that Washington and Seoul have been discussing “corresponding measures” that could be taken in response to the North’s progress on denuclearization. Incentives could include a formal declaration of the end of the 1950-1953 Korean War, humanitarian assistance and a communications channel with the U.S., she said.

The CSIS report argues that any denuclearization deal would need to include the declaration, verification and dismantlement of North Korean missile operating basis.

“While diplomacy is critical, and should be the primary way to resolve the North Korean nuclear problem, any future agreement must take account of all of the operational missile base facilities that are a threat to U.S. and South Korean security,” the report said.

“Have to negotiate *existing* capabilities,” tweeted Victor Cha, former director for Asian Affairs in the White House National Security Council, and one of the report’s authors. “Not just past or future ones. You can’t 'wing' the next summit.”