MANILA (REUTERS) - Philippine President Rodrigo Duterte has rebuffed a call from China to withdraw vessels from disputed areas of the South China Sea and said he would not bow to pressure, even if it jeopardises his friendship with Beijing.

The Philippines has boosted its presence in contested areas of its exclusive economic zone, including Thitu island, near to a Chinese military installation, in defiance of the months-long presence of hundreds of Chinese boats it believes are manned by militia.

Mr Duterte's remarks in a televised address aired on Friday (May 14) come as pressure builds on him to abandon his pursuit of close ties with China and stand up to what his defence chiefs say are blatant provocations.

"We have a stand here and I want to state it here and now again that our ships there... we will not move an inch backward," Mr Duterte said.

China last month said the Philippines must "stop actions complicating the situation and escalating disputes" in response to a rare maritime exercise conducted by the Philippines.

"I do not want a quarrel, I do not want trouble. I respect your position, and you respect mine. But we will not go to war," Mr Duterte said.

"I will not withdraw. Even if you kill me. Our friendship will end here."

There was no immediate response to a request for comment from the Chinese embassy in Manila.

Mr Duterte has been criticised for refusing to press China to abide by a 2016 arbitration ruling on the South China Sea that went in Philippines' favour.

He drew flak last week for saying the landmark award was just a "piece of paper" he could throw in the trash.

In his televised address, he said he "believes in the entirety" of that ruling.