Yemen's exiled President Abedrabbo Mansour Hadi on Thursday paid tribute to loyalist forces as they pushed an offensive against Iran-backed rebels in the country's second city of Aden.
Hadi's comments came as officials said preparations were under way for a government delegation to visit Aden to assess the damage from four months of fighting.
"Aden will be the key to Yemen's salvation," Hadi said in a televised address marking the end of the holy Muslim fasting month of Ramadan.
"From Aden we will regain (control) of all of Yemen," said Hadi, praising the "resistance" of pro-government forces who are battling to oust the Shiite Huthi rebels and their allies from the southern city.
The rebels entered Aden in March, after seizing control of the capital Sanaa, forcing Hadi and his government into exile in neighbouring Saudi Arabia.
On Tuesday loyalist forces launched Operation Golden Arrow, one of their biggest counter-offensives so far.
Since then they have recaptured Aden airport and much of the surrounding Khormaksar diplomatic district, as well as the provincial government headquarters.
The southern militiamen of the Popular Resistance, backed by reinforcements freshly trained and equipped in Saudi Arabia, have also gained ground in Mualla.
On Thursday they also recaptured the rebel-held district of Crater near the presidential palace in Aden, loyalist General Abdullah al-Subeih said, in an operation during which 71 rebels surrendered.
The Saudi-led coalition, which has been waging air strikes against the insurgents since March, provided air cover.
Officials said the pro-government fighters used loudspeakers to offer rebels in the districts of Crater, Mualla and Khormaksar safe passage out of the city if they lay down their arms.
The rebels tried to bring in reinforcements from the central province of Baida overnight but were bombed by coalition warplanes.
The coalition also hit rebel positions on Aden's northern and eastern outskirts and in other districts of the city, military sources and witnesses said.
The retreating rebels again pounded Aden oil refinery with Katyusha multiple rocket launchers, sparking a new blaze at the facility, which has 1.2 million tonnes of crude in storage, an oil official said.
Signup to our newsletter and follow us on Facebook and Twitter!
Thick smoke formed over the refinery -- Yemen's largest -- and residents of nearby areas were evacuated, witnesses said.
- 'Most parts of city secure' -
With the rebels in retreat, the exiled government announced plans late on Wednesday for Interior Minister Abdo al-Houdaithi, Transport Minister Badr Baslama, and Deputy Health Minister Nasser Baoum to head to Aden.
Government spokesman Rajih Badi told AFP that they would leave Riyadh "in the coming hours... to assess the situation and the magnitude of the destruction."
"Most parts of the city are secure," he said, adding the government was working on securing remaining districts.
But officials in Aden said there was still no sign of the delegation by Thursday afternoon.
"No minister from Hadi's government has arrived in Aden," a provincial official told AFP.
Aden airport security chief Abdullah Qayed said "no plane has landed at the airport".
Hadi adviser, Yassin Makawi, said however that "preparations are under way for the arrival of the official delegation in Aden". He gave no further details.
Aden was Hadi's last refuge after he fled the rebel-controlled capital Sanaa earlier this year as the rebels took over the government and launched an offensive in which they seized much of the country.
Much of the city has been reduced to rubble by the four months of ferocious fighting, with the rebels backed by former soldiers loyal to ousted president Ali Abdullah Saleh.
Efforts by the United Nations -- which declared Yemen a level-3 humanitarian emergency, the highest on its scale -- to clinch a ceasefire to allow the delivery of desperately needed relief supplies foundered.
More than 21.1 million people -- over 80 percent of Yemen's population -- need aid, with 13 million facing food shortages, while access to water has become difficult for 9.4 million people.
Four months of fighting and air strikes have killed more than 3,200 people.
Also on Thursday, Saudi ally the United Arab Emirates announced the death of one of its officers who was taking part in the coalition against the Yemeni rebels.