MANILA - The Philippines expressed concern on Monday about China's testing of a massive dredging ship, saying it would track its activities closely, despite Beijing's assurances it would not develop areas where it has competing claims with Manila.

China, which has poured billions of dollars into building artificial islands to strengthen its sovereignty claims across most of the South China Sea, has started testing a new ship designed to boost its land reclamation capability.

"The mere presence is a little bit concerning," Defense Secretary Delfin Lorenzana told reporters. "Where it is going, we do not know."

Military officials said the ship, Tian Kun, had a deck the size of nine basketball courts and would become Asia's largest dredging vessel.

China claims almost the entire South China Sea, through which more than $3 trillion of seaborne trade passes each year. Brunei, Malaysia, the Philippines, Taiwan and Vietnam also have conflicting claims in the area.

Lorenzana said troops deployed on nine Philippine-claimed features in the South China Sea had been ordered to monitor the movements of Chinese navy, coastguard and fishing boats in the Spratly islands.

"We are constantly monitoring the movement of the ship," he added. "We have also our air patrol going regularly, so we will be able to monitor movement of this so-called very big dredger ship."

The testing of the dredger comes ahead of two major international meetings in Vietnam and the Philippines this week and the next, set to be attended by China and the United States.

In August, the foreign ministers of Southeast Asia and China adopted a negotiating framework for a code of conduct in the South China Sea, a move they hailed as progress but which critics saw as a tactic to buy China time to consolidate its maritime power.

All parties say the framework is only an outline for how the code will be established, but critics say the failure to outline as an initial objective the need to make the code legally binding and enforceable, or have a dispute resolution mechanism, raises doubts about how effective it will be.

In Beijing, Chinese Assistant Foreign Minister Chen Xiaodong said talks on the framework had achieved important progress and there would be results at the Manila summit of Southeast Asian nations, attended by Chinese Premier Li Keqiang.

"Whether the code is binding, or how it would be binding, and what the code looks like in its final form, depends on the outcome of the talks between China and the Association of Southeast Asian Nations," Chen told reporters.

"It can't be decided by a single party."

Chinese President Xi Jinping will attend the other meeting, of Asia-Pacific leaders in Vietnam.