However, Heads of State from the Economic Community of West African States (ECOWAS), a regional political body, intervened and sent a mediation team to settle the impasse and urged him to step down but all those efforts proved fruitless.
Jammeh was defeated by opposition coalition leader Adama Barrow but rejected the results one week after the December 1 vote, claiming the process was tainted with unacceptable irregularities.
Mai Ahmad Fatty told journalists in neighboring Senegal that already they have determined Jammeh made off with more than $11.4 million during a two-week period alone.
But a top Barrow adviser, Mai Ahmad Fatty, said the declaration did not have the new leader's approval.
Jammeh's exile clears the way for Gambia's first peaceful and democratic transfer of power since the nation gained independence in 1965.
The Gambia's former leader has left the country for Equatorial Guinea, after finally agreeing to step down from office.
"No legislative measures" would be taken that would infringe the "dignity, security, safety and rights" of Jammeh or his family, it said, noting that he could return when he pleased and that property "lawfully" belonging to him would not be seized.
Global rights lawyer Reed Brody said the declaration "doesn't give him an amnesty, and under worldwide law in fact you can't amnesty certain crimes like torture and massive or systematic political killings".
The strongman's departure ended six weeks of political turmoil sparked by Jammeh's refusal to accept his election defeat to new Gambian President Adama Barrow.
Defeated Gambian President Yahya Jammeh has relinquished claims on power and agreed to go into exile.
With Jammeh gone, a country that had waited in silence during the crisis sprang back to life. The group assembled a multinational military force including tanks that rolled into Gambia Thursday.
He said Barrow had seen what they understood to be a draft document and rejected it as a "non-starter".
The focus for Gambians has now turned to calling Jammeh to account for some of his alleged human rights abuses.
An additional 45,000 people fled to Senegal amid growing fears of unrest in the wake of last month's election, according to the United Nations.
The fears for Barrow's security were because Jammeh has always been accused by human rights groups of heading a government that tortured opponents and silenced dissent.