By Tim Cocks and Emma Farge
BANJUL/DAKAR (Reuters) - West African armies halted an operation in Gambia aimed at installing the country's new president, Adama Barrow, on Thursday so regional leaders could make one last attempt to convince longtime ruler Yahya Jammeh to step aside.
Barrow took the oath of office on Thursday at Gambia's embassy in Senegal, calling for international support from West Africa's ECOWAS bloc, the African Union and the United Nations.
A regional military force launched an intervention effort, dubbed Operation Restore Democracy, shortly after the former opposition figure was sworn in.
"We think that up until the last minute there is still a solution through dialogue," said Marcel de Souza, head of the ECOWAS commission, explaining the decision to suspend the advance to reporters in Dakar late on Thursday.
During his inauguration speech Barrow appealed to ECOWAS, the African Union and the United Nations for support for his government and Gambia's people.
"This is a day no Gambian will ever forget," Barrow said after taking the oath, which was administered by the president of Gambia's bar association. "Our national flag will now fly high among the most democratic nations of the world."
Jammeh, in power since a 1994 coup, initially conceded defeat to Barrow following a Dec. 1 election before back-tracking, saying the vote was flawed.
De Souza said a total of 7,000 troops from Senegal, Nigeria, Ghana, Togo and Mali would be involved in the operation. Troops had already entered Gambia from the southeast, southwest and north before they were ordered to stop.
The advance will resume at noon (1200 GMT) on Friday if Jammeh still refused to leave, he said. Barrow will return to Gambia once the operation is over.
The U.N. Security Council on Thursday backed ECOWAS's efforts to ensure Barrow assumes power, and the United States said it supported the intervention.
U.N. Secretary-General Antonio Guterres in a statement pledged "his full support for his (Barrow's) determination, and ECOWAS's historic decision, with the unanimous backing of the Security Council, to restore the rule of law in The Gambia so as to honor and respect the will of the Gambian people."
ECOWAS and the African Union previously said they would recognize Barrow from Thursday, and nations including the United Kingdom and France were quick to congratulate him.
"THE DICTATOR IS OUT"
Following Barrow's swearing in, hundreds of Gambians celebrated in the streets of Banjul, the capital, cautiously at first, and then gradually in larger numbers as they realized the security forces looking on were not going to open fire.
Army chief General Ousman Badjie, who had publicly stood by Jammeh, was seen smiling on the streets wading through a mass of jubilant Banjul residents shouting and dancing.
Cars raced up and down the highway lined with iron-roofed shops in the pro-Barrow Serrekunda district of Banjul, with horns honking and people hanging out the windows.
"The dictator is out," shouted pharmacist Lamine Jao, 30, as others cheered and whistled in agreement. "It's just a question of time. We'll soon flush him out. Believe me."
During the brief inauguration speech, Barrow asserted his new role as commander and chief of Gambia's armed services, ordering soldiers to stay calm and remain in their barracks. Those who did not would be considered rebels, he said.
ECOWAS will send a team led by Guinea's president, Alpha Conde, and including the presidents of Liberia and Mauritania to Banjul on Friday, de Souza said.
If the mission succeeds, Jammeh will travel to Guinea before choosing a country of exile.
"It's out of the question that he stays in place. ... We propose that he leaves in an honorable manner and with respect," said de Souza, who added that regional leaders were open to the possibility of an amnesty as part of a deal.
It was unclear what Jammeh's next move would be. He has so far ignored pressure to step aside and offers of exile.
He now faces almost total diplomatic isolation and a government riddled by defections. In the biggest loss yet, Vice President Isatou Njie Saidy, who has held the role since 1997, quit on Wednesday.
In a statement released late on Thursday, Jammeh announced he was dissolving his government - a 19-member Cabinet, half of whose members had already resigned - and pledged to name a new one "in due course."
Fearing unrest, thousands of Gambians have fled in recent weeks, the United Nations estimates.
Tour companies, meanwhile, have rushed to evacuate hundreds of European tourists.
Gambia's long, sandy beaches have made it a prime destination for tourists, but Jammeh, who once vowed to rule for "a billion years," has earned a reputation for rights abuses and stifling dissent.
(Additional reporting by Nellie Peyton and Diadie Ba in Dakar, Felix Onuah in Abuja, Michelle Nichols at the United Nations and John Irish in Paris; Writing by Joe Bavier and David Lewis; Editing by Dominic Evans and Leslie Adler)