Japanese Prime Minister Shinzo Abe, center, arrives for a meeting with President Donald Trump and Australian Prime Minister Malcolm Turnbull at the ASEAN Summit at the Sofitel Philippine Plaza, Monday, Nov. 13, 2017, in Manila, Philippines. Trump is on a five country trip through Asia traveling to Japan, South Korea, China, Vietnam and the Philippines. (AP Photo/Andrew Harnik)

MANILA, Philippines - Leaders of Southeast Asian countries and China agreed Monday to begin negotiations on a "code of conduct" aimed at controlling aggressive actions in the disputed South China Sea, a step they described as a milestone, but some experts said was unlikely to ensure compliance.

Leaders from the Association of Southeast Asian Nations will also sign an accord protecting migrant workers coming from poorer countries in the region during a two-day summit that opened Monday in Manila, Philippine President Rodrigo Duterte said.

The ASEAN leaders will express "grave concern" over North Korea's development of "weapons of mass destruction, including nuclear and chemical weapons, and ballistic missile technologies," and strongly condemn terrorism, according to a draft of a summit communique seen by The Associated Press.

Department of Foreign Affairs spokesman Robespierre Bolivar said China and the 10 ASEAN countries agreed to start negotiations on the code of conduct and would issue a statement later Monday with more details.

A separate statement to be issued after a meeting between the ASEAN leaders and Chinese Premier Li Keqiang said the approval last August of a framework for the code of conduct was "an important milestone," and both sides anticipated an early conclusion of the agreement.

"While the situation is calmer now, we cannot take the current progress for granted," the leaders said in the draft statement.

It's "important that we co-operate to maintain peace, stability, freedom of navigation in and over-flight above the South China Sea in accordance with international law," they said. "It is in our collective interest to avoid miscalculations that could lead to escalation of tensions."

However, Gregory Poling, a South China Sea expert with the Center for Strategic and International Studies in Washington, said, "The idea that this is going to lead to a binding way to manage things like fisheries depletion and oil and gas development or coast guard co-operation is a fantasy, and Beijing knows that."

"It took 15 years to negotiate a one-page outline that just restated the exact same thing they're going to do with DOC," he said, referring to a nonbinding Declaration on the Conduct of Parties in the South China Sea that was signed in 2002. "If you look at the framework agreement signed earlier this year, there's nothing there."

China has opposed a legally binding code, and Southeast Asian diplomats said even ASEAN is not unanimous in seeking a binding set of rules.

China, Taiwan and four ASEAN member states — Brunei, Malaysia, the Philippines and Vietnam — have overlapping claims in the waterway, which straddles busy international sea lanes and potentially has vast undersea deposits of oil and gas.

The U.S. is not a claimant but has declared it has a national interest in ensuring that the disputes are resolved peacefully in accordance with international law and that freedom of navigation and overflight are guaranteed. China has opposed what it calls U.S. meddling in an Asian dispute.

In a speech at the start of the meeting, Li insisted on China's peaceful intentions and said it was the first country to accede to a 1976 nonaggression treaty signed by ASEAN. "We are committed to working with ASEAN to be good neighbours, good friends and good partners that always stand together, rain or shine," Li told the ASEAN leaders.

U.S. President Donald Trump gave similar assurances in a separate meeting with the ASEAN leaders and tried to cozy up with Duterte, the summit host and chairman. Addressing the Philippine leader by his first name, Trump thanked him for his "incredible hospitality" and a welcome dinner Sunday at which Filipino singers sang, and Duterte as well, after he was egged on by the American president.

"The talent at that show, I assume mostly from the Philippines, was fantastic," Trump said. "And you were fantastic also. ... We couldn't tell the difference."

After belting out a Tagalog love song with a Filipina singer during the dinner, Duterte said he sang "upon the orders of the commander in chief of the United States," setting off laughter and applause.

In a meeting with Duterte on Monday, Trump did not express concern about the Philippine president's crackdown on illegal drugs, Duterte spokesman Harry Roque told reporters.

The crackdown has left thousands of suspects dead in what human rights groups say were extrajudicial killings.

News from © The Associated Press, 2017