WASHINGTON  

Former National Security Advisor John Bolton reportedly slammed President Donald Trump's foreign policy strategy Wednesday.

Bolton made the remarks while addressing attendees at a closed-door lunch at the Gatestone Institute in New York, U.S. online news site Politico reported.

He said Trump’s move to invite the Taliban for peace talks at Camp David in Maryland sent a "terrible signal" and was "disrespectful" to the victims of 9/11 because the Taliban had harbored al-Qaeda, according to the report.

Also, citing two attendees, Politico reported that Bolton said any negotiations with North Korea and Iran were "doomed to failure."

"He ripped Trump, without using his name, several times," said one anonymous attendee.

In addition, Bolton repeatedly said that Trump’s failure to respond to Iran's downing of an American drone in June had led to Tehran’s aggression in recent months, the report said.

Trump abruptly ousted Bolton last week following a tenure marked by major policy splits with Trump, a fact the president pointed to in stark terms in the aftermath of the ouster.

Bolton has long advocated for a hawkish approach to foreign policy, which is at odds with the president's penchant for isolationism.