BEIJING, April 23 (UPI) -- China's top experts on North Korea told U.S. specialists that Pyongyang could double its nuclear arsenal to 40 warheads by 2016.
The numbers ran far higher than previous U.S. estimates and could mean North Korea has enough weapons to pose a threat to U.S. and regional security, The Wall Street Journal reported.
Chinese technical, political and diplomatic experts who met with their U.S. counterparts in February said North Korea had 20 warheads at the end of 2014, with 20 more under development that could be ready by 2016.
Washington has mutual defense treaties with Seoul and Tokyo, and an attack on either country is regarded as an attack on the United States.
Siegfried Hecker, a professor at Stanford University and former head of the Los Alamos National Laboratory, said the more North Korea believes it has a fully functional nuclear arsenal the "more difficult it's going to be to walk them back from that."
A nuclear North Korea could push the United States to take on countermeasures, such as the deployment of a THAAD missile defense system.
Earlier this month, Adm. William Gortney of the U.S. Northern Command said defense officials believe North Korea can mount a nuclear warhead on an intercontinental ballistic missile called the KN-08. Experts say the missile has a range of about 5,600 miles and could reach the western coast of the United States.
U.S. National Security Council spokesman Patrick Ventrell said China should use its influence to curtail North Korea provocations, but Beijing's coordination with Pyongyang may be on the decline.
Quansheng Zhao, a professor of international relations at American University, said Beijing's influence over Pyongyang has significantly waned because of Pyongyang's prioritization of bilateral talks with Washington.
Yonhap reported the Chinese estimate of North Korea's nuclear arsenal exceeds February estimates made by experts at the U.S.-Korea Institute at Johns Hopkins University, who said North Korean has 10 to 16 weapons.
On Wednesday, Washington and Seoul announced a revised treaty to deny but not permanently rule out South Korea's right to enrich uranium or reprocess spent nuclear fuel, even for peaceful purposes, reported The New York Times.