Yemeni President Abd-Rabbu Mansour Hadi has returned to Aden from exile in Saudi Arabia, with officials saying he would oversee campaigns against the Houthi fighters who control the capital, Sanaa.
Hadi's arrival on Tuesday came after a series of setbacks for the Saudi-led campaign to reinstate him, with offensives on the ground faltering and armed groups such as the Islamic State of Iraq and the Levant (ISIL) group increasingly active.
Saudi-led coalition forces launched an offensive on Monday with local forces to push Houthi fighters out of Taiz, Yemen's third largest city, and Hadi is said to have come to help to oversee it.
After landing in the provisional capital, Hadi went straight to the palace to "supervise" the offensive aimed at retaking rebel-controlled Taiz province, AFP news agency reported.
His return comes just days after Khaled Bahah, the Yemeni prime minister, announced the return of his government to Aden.
It is Hadi's second visit to Aden since a loose alliance of anti-Houthi fighters, backed by troops from the UAE, drove the rebels out of the southern city in July.
His previous visit in September, after six months in exile in Riyadh, lasted only three days, and it was not immediately clear how long the internationally recognised president would stay this time.
Offensives by anti-Houthi fighters backed by a coalition of Arab Gulf states appear bogged down in central Yemen and east of Sanaa.
In the south, the Houthis have reportedly regained ground in recent weeks.
Bahah left Aden for Saudi Arabia in October after bomb attacks claimed by ISIL targeted his government's residence and buildings used by UAE troops.
Al-Qaeda fighters are also reported to be active in the city, and they control areas of southeastern Yemen including the regional capital, Mukalla.
Saudi Arabia and its allies launched a war with Yemen's Shia Houthi forces in March, when Hadi first fled Aden to Riyadh.
Although the war began with air strikes, the Saudi-led coalition have, increasingly, begun to provide ground forces in the war.
The UN says that some 5,000 people, more than half of them civilians, have been killed in Yemen since the Saudi-led campaign began.