BANJUL, Gambia — Exiled Gambian ruler Yahya Jammeh stole millions of dollars in his final weeks in power, plundering the state coffers and shipping out luxury vehicles by cargo plane, a special adviser for the new president said Sunday.

Meanwhile, a regional military force rolled in, greeted by cheers, to secure this tiny West African nation so that democratically elected President Adama Barrow could return home. He remained in neighboring Senegal, where he took the oath of office Thursday because of concerns for his safety.

At a news conference in the Senegalese capital, Barrow’s special adviser Mai Ahmad Fatty told journalists that the president “will return home as soon as possible.”

Underscoring the challenges facing the new administration, Fatty confirmed that Jammeh made off with more than $11.4 million during a two-week period alone. That is only what they have discovered so far since Jammeh and his family took an offer of exile after more than 22 years in power and departed late Saturday.

“The Gambia is in financial distress. The coffers are virtually empty. That is a state of fact,” Fatty said. “It has been confirmed by technicians in the ministry of finance and the Central Bank of the Gambia.”

Fatty also confirmed that a Chadian cargo plane had transported luxury goods out of the country on Jammeh’s behalf in his final hours in power, including an unknown number of vehicles.

Fatty said officials at the Gambia airport have been ordered not to allow any of Jammeh’s belongings to leave. Separately, it appeared that some of his goods remained in Guinea, where Jammeh and his closest allies stopped on their flight into exile.

Fatty said officials “regret the situation,” but it appeared that the major damage had been done, leaving the new government with little recourse to recoup the funds.

The unpredictable Jammeh, known for startling declarations like his claim that bananas and herbal rubs could cure AIDS, went into exile under mounting international pressure, with a wave to supporters as soldiers wept. He is now in Equatorial Guinea, home to Africa’s longest-serving ruler and not a state party to the International Criminal Court.

Jammeh’s dramatic about-face on his December election loss to Barrow, at first conceding and then challenging the vote, appeared to be the final straw for the international community, which had been alarmed by his moves in recent years to declare an Islamic republic and leave the Commonwealth and the ICC.

Barrow’s adviser disavowed a joint declaration issued after Jammeh’s departure by the United Nations, African Union and West African regional bloc ECOWAS that bestowed a number of protections upon Jammeh, his family and his associates — including the assurance that their lawful assets would not be seized.

“As far as we’re concerned, it doesn’t exist,” Fatty said.

The declaration also said Jammeh’s exile was “temporary” and that he reserved the right to return to Gambia at the time of his choosing.

Although the declaration was written to provide Jammeh with maximum protection, it doesn’t give him amnesty, according to international human rights lawyer Reed Brody.

“Under international law in fact you can’t amnesty certain crimes like torture and massive or systematic political killings,” he said in an email. “Depending where Jammeh ends up, though, the real obstacles to holding him accountable will be political.”

Barrow will now begin forming a Cabinet and working with Gambia’s national assembly to reverse the state of emergency Jammeh declared in his final days in power, said Halifa Sallah, spokesman for the coalition backing the new leader.