MANILA • Philippine President Rodrigo Duterte said yesterday that he could not stop China from building on a disputed shoal near his country's west coast because it was too powerful.

The mayor of China's Sansha city has reportedly said that his country will set up an environmental monitoring station on Scarborough Shoal, which China seized from the Philippines in 2012.

"We cannot stop China from doing (these) things," Mr Duterte told journalists, when asked about the reports.

"What do you want me to do? Declare war against China? I can't. We will lose all our military and policemen tomorrow and we (will be) a destroyed nation," he said at a press conference, before departing for a visit to Myanmar.

Mr Duterte said he would tell the Chinese: "Just keep it (the waters) open and do not interfere with our coast guard."

He also brushed aside concerns over Chinese survey ships seen near Benham Rise - waters east of the main Philippine island of Luzon, which have been recognised by the United Nations as indisputably the Philippines' territory.

Earlier this month, Defence Secretary Delfin Lorenzana said he was very concerned that the ships had been seen at that location, sometimes for as long as a month.

But Mr Duterte said: "So what if they stop there? They admit it is within the territory of the Philippines. That does not satisfy you?"

His predecessor, Mr Benigno Aquino, had actively challenged China's claim to control most of the South China Sea, despite counter-claims by several other nations.

However, Mr Duterte, who took office last year, has reversed that policy and is seeking billions of dollars worth of investments and grants from Beijing.

"We are now improving the economy because of the help of China. Why will you be so shameless just because they are passing by?" he said.

AGENCE FRANCE-PRESSE