Afghanistan’s ex-president Ashraf Ghani fled the country over the weekend as the Taliban advanced on Kabul and ultimately assumed power. Saleh said that according to the nation’s 2004 constitution, he is now the acting president of the Islamic Republic of Afghanistan since Ghani is in exile outside of the country in an unknown location.

On Tuesday, Saleh tweeted that the constitution states that “in absence, escape, resignation or death of the President the FVP [first vice president] becomes the caretaker President. I am currently inside my country & am the legitimate caretaker President. Am reaching out to all leaders to secure their support & consensus.”

Saleh previously served as Ghani’s state minister for security reforms and as interior minister before joining Ghani’s election team in 2019. The final election results from that year were delayed until February 2020, when Ghani was officially announced as the winner. He was sworn in the following month, with Saleh as his first vice president and Sarwar Danish as the second vice president.

On Tuesday, Saleh wrote that it was “futile to argue” with President Joe Biden. He said it was up to the people of Afghanistan to prove that their country “isn’t Vietnam” and that the Taliban isn’t “even remotely” like the Vietcong.

He said that “unlike US/NATO,” the Afghan people haven’t lost hope in their future. “Useless caveats are finished,” his message continued. “JOIN THE RESISTANCE.”

Saleh has made numerous other statements on Twitter in recent days. On Sunday, he wrote that he would “never, ever & under no circumstances bow” to the Taliban.

“I won’t disappoint millions who listened to me. I will never be under one ceiling with Taliban. NEVER,” he added.

Saleh also wrote last week of a security meeting chaired by Ghani. In that message, he spoke of his pride in the armed forces of Afghanistan and said that government leaders—“with conviction and resolve”—“STAND FIRM AGAINST TALIBAN TERRORISTS.”

When Ghani fled the country, there were reports he left with piles of cash, and rumors emerged about whether the United States played a role in his escape. He later defended leaving Afghanistan on Facebook, saying his departure had prevented more bloodshed.

Ghani wrote, in part: “If I had stayed, countless of my countrymen would be martyred and Kabul would face destruction.”