Duterte is scheduled to meet President Donald Trump next week in Manila during the Association of Southeast Asian Nations (ASEAN) summit there.
"I want to pass on words of thanks from the Philippine people for the timely aid that Russian Federation provided by giving us trucks and weapons", Duterte said on November 10 as the two met on the sidelines of the APEC summit in Danang, Vietnam.
Despite activists having long criticised the United States for what they see as an unrelenting American control over the Philippines, Duterte changed his stance toward the U.S. after Trump's inauguration past year.
"It was brief meeting".
Presidential spokesman Harry Roque said the talk between Duterte and Xi was straightforward.
It remains unclear whether Duterte's remarks on homicide were in jest.
The two lawmakers stressed that the Philippines, while it continues to address the drug problem, should ensure that there will be no human rights violation.More news: Vontae Davis: Benching shows 'no respect' from Colts
"It was very warm and cordial", said Mr Roque.
Across town, protesters from the militant group Bagong Alyansang Makabayan (Bayan) rallied outside Trump Towers, claiming the USA president had the intention of using the Philippines' territory to install more American military bases and that his heightened involvement in the country's affairs could drag them into war.
But Aguirre and officials of the Bureau of Immigration under his office admitted they have yet to receive an order from Duterte banning the entry of the two USA lawmakers into the country.
As part of the ongoing APEC Economic Leaders' Week, the CEO summit is the largest annual event of the business community in the Asia-Pacific, which culminates in the APEC Economic Leaders' Meeting on Friday and Saturday.
In other photos, Duterte was seen shaking hands with Mexican President Enrique Peña Nieto and South Korean president Moon Jae-in.
Well, given Trump's apparent fondness for world dictators, it doesn't seem Trump will likely be bothered by not getting to discuss the topic with Duterte - after all, the US commander-in-chief has praised Egypt's President Abdel-Fattah el-Sisi, who is accused of sanctioning the killings of some 800 protesters in a single day, for doing "a fantastic job in a very hard situation". It is their first meeting since Duterte visited Moscow, Russia in mid-May.