Donald Trump appeared on Saturday to confirm the death of Qassim al-Rimi, the leader of an al-Qaida affiliate in Yemen, through a series of tweets.

According to a New York Times report on Friday, Rimi, 41 and the leader of the splinter-group al-Qaida in the Arabian Peninsula, or AQAP, is believed to have been killed in a drone strike in Wadi Abedah in the centre of the war-torn country last month.

On Saturday, Trump was at his Florida resort. Before the strike had been publicly confirmed by either US authorities or AQAP, he retweeted posts from an intelligence analyst and a reporter that discussed reports of Rimi’s death. He then tweeted a picture of his golf swing.

Contacted by the Guardian, a Department of Defense spokesman offered no information.

Politico quoted a Pentagon official as saying: “This was not a DoD operation.”

Rimi was considered a potential successor to Ayman al-Zawahiri, the Egyptian leader of al-Qaida’s strategic operations.

In 2006, Rimi and other AQAP members escaped from prison in Yemen to establish what the US considered to be one of al-Qaida’s most vigorous local branches, orchestrating attacks on pipelines carrying oil and gas to terminals in the south of the country.

In 2013, in a message “to the American nation”, Rimi said: “Your security is not achieved by despoiling other nations’ security or by attacking and oppressing them.”

Americans should “leave us with our religion, land and nations and mind your own internal affairs”, he said.

Rimi reportedly became leader of AQAP following a 2015 drone strike that killed Nasir al-Wuhayshi.

In 2017, days after a special forces raid on a compound in Yemen in which a US soldier was killed, Rimi taunted Trump, saying in a recorded message: “The new fool of the White House received a painful slap across his face.”

In an attempt to prevent al-Qaida from establishing a secure base in Yemen, the US recorded 131 strikes there in 2017 but only 36 in 2018. In that year, US officials said a CIA drone strike killed Ibrahim al-Asiri, a senior al-Qaida bomb maker behind the “underwear bomb” attempt on a flight on Christmas Day in 2009.

In January last year, a US strike killed Jamal al-Badawi, an al-Qaida operative linked to the 2000 attack on the USS Cole while it was being refuelled in Aden.

Yemen has been gripped by civil war since 2015. This week, Mike Pompeo, the secretary of state, said the US was “alarmed” by a recent increase in violence in Yemen.

The violence “produces instability that terrorist groups and other malign actors can exploit for their own purposes”, Pompeo said.