SEOUL (Reuters) - South Korean President Moon Jae-in said on Tuesday it would not be easy for reclusive North Korea to destroy its nuclear arsenal quickly, even if wanted to, given its weapons programs were so developed.

South Korea's President Moon Jae-In delivers a statement during the 19th Association of Southeast Asian Nations (ASEAN)-Republic of Korea Summit on the sidelines of the 31st ASEAN Summit and Related summits at the Philippine International Convention Center (PICC) in Manila, Philippines November 13, 2017. REUTERS/Noel Celis/Pool

North Korea is under heavy international pressure to end its weapons programs, pursued in defiance of U.N. Security Council resolutions. But it has vowed never to give up its nuclear arsenal.

Speaking to reporters in the Philippines, Moon said that if North Korea agreed to hold talks, negotiations could be held with all options open.

“If talks begin to resolve the North Korea nuclear issue, I feel it will be realistically difficult for North Korea to completely destroy its nuclear capabilities when their nuclear and missile arsenal are at a developed stage,” Moon said in a briefing.

“If so, North Korea’s nuclear program should be suspended, and negotiations could go on to pursue complete denuclearization.”

Moon’s remarks were made available by the presidential Blue House.

Last week, the North said it did not oppose dialogue, but would “never put the issue related to the supreme interests of the DPRK and security of its people on the bargaining table”.

“We are not interested in such dialogue and negotiations in the least,” the North’s official news agency said, referring to the country by its official name, the Democratic People’s Republic of Korea.

The North defends the programs as a necessary defense against U.S. plans to invade. The United States, which has 28,500 troops in South Korea, a legacy of the 1950-53 Korean war, denies any such intention.

U.S. President Donald Trump has traded insults and threats with North Korean leader Kim Jong Un as North Korea races toward its goal of developing a nuclear-tipped missile capable of reaching the United States.

Trump threatened in his maiden U.N. address to “totally destroy” North Korea if the United States was threatened and has said the time for talking, the policy of previous U.S. administrations, is over.

Moon reiterated his stance that now was the time to increase pressure on North Korea so that it would come to talks.

He said differences in understanding between South Korea and China, North Korea’s lone major ally, regarding the deployment of the U.S. Terminal High Altitude Area Defense (THAAD) system on South Koran soil had not been resolved.

“China has not said it has changed its stance to agree to THAAD and still says THAAD infringes on its security. We have, in turn, explained THAAD is not aimed at China but only toward curbing North Korea’s nuclear and missile provocations,” he said.

Last month, South Korea and China agreed to end a year-long standoff over THAAD which had seen South Korean companies doing business in China suffer from retaliation against the system’s deployment.