Philippine President Rodrigo Duterte said on Friday he was not severing ties with his country's long-time ally the United States, but merely pursuing a more independent foreign policy by strengthening relations with China.

A day after he provoked fresh diplomatic alarm by announcing his "separation" from Washington, Duterte struck a more conciliatory tone as he arrived back in the Philippines after a four-day visit to Beijing.

"It is not severance of ties. When you say severance of ties, you cut diplomatic relations. I cannot do that," the Philippine leader told reporters at a midnight news conference in his southern home city of Davao.

"It's in the best interest of my countrymen to maintain that relationship."

On Thursday, Duterte had told Chinese and Philippine business people at a forum in Beijing's Great Hall of the People that America had "lost now", as he sought what he calls a new commercial alliance with China. "I announce my separation from the United States," he had said, to sustained applause, adding he would also seek closer ties with Russia.

Clarifying his comments on Friday, he said that what he meant was that Manila's foreign policy need not always "dovetail" with Washington. "As in separation, what I was really saying was separation of foreign policy," he said.

"In the past, and until I became president, we always follow what the United States would give the cue."