Shortly afterwards, he promised a rapid return to Sanaa. Marem declined to specify how long Hadi would stay in Aden, where he does not have strong popular support.
This has been a recurring problem with attempts to start peace talks, as the Saudis have maintained that any talks be conditional on the Houthis first disarming and surrendering the entire country to their side.
Prime Minister Khaled Bahah returned from exile to the main southern city of Aden last week, but has acknowledged his government still faces major challenges.
Ahmed Ameen, 23, said he would not forget the day, with Mr Hadi claiming that Al Qaeda militants were no longer in Aden.
The rebels still control much of northern and central Yemen.
The Marib offensive began after an early-September missile strike on a base in the province killed 67 coalition soldiers, including 52 Emiratis.
The Houthis say that they are fighting against alleged corruption of the Hadi regime while the Gulf states are wary of Iran’s growing influence in the region.
Aerial bombardments and ground clashes have killed more than 4,800 people since March, about half of them thought to be civilians. The United Nations aid chief has called the scale of human suffering “almost incomprehensible”.
In May, USA officials said Houthi rebels were holding at least four Americans, including three private sector employees and one Yemeni-American.
The death toll is likely to rise because some people are missing, another medical source said, as rescuers combed the rubble.
Elsewhere, a USA drone strike killed two suspected members of al-Qaida east of Sanaa, an official said.
Scott Darden, 45 – who has a 10-year-old son – was to be reunited with his wife in Oman on Monday, company spokesman Ken Luce told AFP.
Muscat: United States has thanked the Government of Oman under the leadership of His Majesty Sultan Qaboos bin Said Al Said for assisting with the safe passage of two USA citizens from Yemen to Oman.
The embattled Hadi’s return reflects how the momentum of a conflict that accelerated in March with Saudi-led airstrikes has shifted away from the Houthis.