South East Asian leaders and Australia's prime minister on Sunday called on North Korea to end its nuclear program urged United Nations countries to fully implement sanctions.

Leaders at the first summit of the Association of Southeast Asian Nations, known as ASEAN, to be held in Australia issued a joint statement with Australia that also called for non-militarization and a code of conduct in the contested waters of the South China Sea, where China has become increasingly assertive.

"We reiterate our support for the complete, verifiable, and irreversible denuclearization of the Korean Peninsula in a peaceful manner as well as initiatives toward establishing peace in the Korean Peninsula," the joint statement said at the end of the weekend summit in Sydney.

On territorial conflicts with China, which like Australia is not a member of ASEAN, the statement said: "We reaffirm the importance of maintaining and promoting peace, stability, maritime safety and security, freedom of navigation and overflight in the region."

"We emphasize the importance of non-militarization and the need to enhance mutual trust and confidence, exercise self-restraint in the conduct of activities and avoid actions that may complicate the situation," the statement said.

China and the five countries that have conflicting territorial claims over the South China Sea — which include four ASEAN countries — plan to negotiate code of conduct in one of the world's busiest waterways aimed at reducing the risks of armed confrontations in the contested territories.

President Donald Trump and South Korean President Moon Jae-in, who are both planning to meet North Korea's leader Kim Jong Un this spring, last week pledged to maintain "maximum pressure" on his authoritarian regime and seek action on giving up his nukes.

Moon is due to meet Kim in April, a prelude to what would be first U.S.-North Korean summit during seven decades of hostility since the 1950-53 Korean War. The Trump-Kim summit was announced two weeks ago.

The ASEAN nations are Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand and Vietnam.