Duterte has faced criticism for his efforts to crack down on drugs in the Philippines.
Duterte last month declared the liberation of Marawi City from Islamist militants after 154 days of fighting, which killed more than 1,100 people, including 165 soldiers, and displaced almost 400,000 residents.
Duterte and Trump talked briefly on the sidelines of the Asia-Pacific Economic Cooperation Leaders' Meeting in Da Nang, Vietnam.
Despite activists having long criticised the U.S. for what they see as an unrelenting American control over the Philippines, Duterte changed his stance toward the USA after Trump's inauguration a year ago.
Duterte said he sees a very bright future for the relationship between the Philippines and China. "What made you think that I am even planning or thinking about visiting your country?"
"That political event [the USA drift towards isolation] is creating opportunities for us that we should take advantage of", he said in an interview with CBC News. "If the Russians and Chinese equipment can be comparable in quality, then they can be excellent alternatives".
Human Rights Watch has pursued its own investigation and said it found inconsistencies in some police reports, namely instances where police asserted self-defence to justify their actions, "contrary to eyewitness accounts that portray the killings as cold-blooded murders".
His latest comments come ahead of him hosting US President Donald Trump and other leaders for the Association of Southeast Asian Nations (ASEAN) summit. During last year's presidential campaign, Trump famously boasted that his supporters were so loyal that, "I could stand in the middle of Fifth Avenue and shoot somebody, and I wouldn't lose not lose any voters". "And I will volunteer to make the Philippines the venue", Duterte said on Thursday, 9 November and stressed that focus of the conference should not just be the prevailing situation in the Philippines alone but across the world. "I'd be happy to slaughter them", he said previously.
Duterte seemed confident he had Trump's backing for his deadly war on drugs.
"I used to do it personally just to show to the guys that if I can do it, so can you".
He said all victims of human rights violations are welcome to attend the summit and air their grievances.
"Human rights, son of a b***h", he said at the time.