Speaking at a military event in his hometown of Davao on Thursday, Duterte said he had received a letter signed by US Secretary of State Mike Pompeo, Secretary of Commerce Wilbur Ross and Secretary of Defense James Mattis.

The Philippine president is opposing an offer by the U.S. defense chief and other top American officials to buy F-16 fighter jets, saying such an acquisition would be “utterly useless”.

The letter, he said, urged Manila to buy Bell combat utility helicopters and Cessna utility aircraft from an American company. What his country needed were attack helicopters and small planes for counter-militancy operations, Duterte said.

He said America’s military equipment has no use for his country, adding the Philippines no longer will accept second-hand weapons from the United States.

"What I need are just propeller-driven planes for anti-insurgency.” he said. “We don't need F-16 and yet they dangle [it] before us after they insulted us.”

Duterte further said there is no guarantee he could get what he has already bought from Washington.

“Prove to me first that you are in utter good faith,” he said arguing that US lawmakers could block arms supplies to Manila whenever they please.

"I would like to remind America all of them...how sure (are they) that I will be able to get what I bought?" said Duterte who pledged not to visit the United States.