U.S. President Donald Trump has developed a friendly relationship with Philippine President Rodrigo Duterte from the two leaders' telephone conversations and exchanges of letters, a senior administration official said on Tuesday.

"I think there's a warm rapport there and he's very much looking forward to his first in-person meeting with President Duterte," the U.S. official told reporters during a background briefing on Trump's Nov. 3-14 trip to Asia.

Duterte is known for his often profanity-laden tirades against the United States, chiding Washington for treating the Philippines "like a dog," despite the two nations' longstanding relationship.