In his latest barb aimed at Washington , Philippines President Rodrigo Duterte alleged possible ouster plots against him Thursday, saying U.S. envoys, in general, spy on his government.

"Most of the ambassadors of the United States, but not all, are not really professional ambassadors. At the same time they are spying, they are connected with the CIA," Duterte said in a television interview. "The ambassador of a country is the number one spy. But [the] ambassador of the U.S., their forte is really to undermine governments."

Duterte was responding to a media report of an alleged U.S. plot to destabilize his government. The Manila Times on Tuesday reported the former U.S. ambassador to the country had prepared a "blueprint to undermine Duterte," citing information from a "highly placed source."

The Times alleges that Philip Goldberg, the previous ambassador to the Philippines, said in a document that the opposition to the government "would need all the political weapons in their arsenal to replace the Duterte administration." He added that Duterte was perhaps vulnerable since he "has no real friends" outside of his region because of his propensity to mock and ridicule. Duterte has personally called Goldberg "gay" and the "son of a whore."

The U.S. State Department swiftly denied this reporting, calling such allegations "false." President Barack Obama appointed a new ambassador to the Philippines, Sung Y. Kim , shortly after Duterte's May election victory. At the time of the appointment, Obama praised the Philippines' "vibrant democracy" and record voter participation. Kim was sworn in as ambassador in November .

The remarks from Duterte are just the latest example of colorful comments or anecdotes from the Philippines president and former longtime mayor of Davao City. His government is conducting a hard-nosed, national crackdown on the drug trade, which Duterte has approvingly compared to the policies of the Third Reich .

On Tuesday , Duterte admitted that earlier in his career he once threw a Chinese rape and murder suspect from a helicopter, and that he is open to doing so again to criminal suspects.