BANGKOK, Thailand — Thailand’s military chief yesterday declared that he had received royal endorsement for the coup that deposed an elected prime minister, but he pledged to appoint a civilian leader within two weeks and stage elections within a year.

Less than 24 hours after tanks and soldiers moved in to remove Thaksin Shinawatra, what appeared to be the final piece of a perfectly executed bloodless strike slotted into place.

A statement read on all national broadcast outlets said: “In order to create peace in the country, the king appoints General Sondhi Boonyaratglin as head of the Council for Political Reform. All people should remain peaceful, and civil servants should listen to orders from General Sondhi from now on.”

General Sondhi, who is head of the armed forces, launched the coup while Mr. Thaksin was in New York at the United Nations.

The ousted prime minister yesterday arrived in London, where one of his daughters studies and the family has an apartment in Kensington.

He was collected from Gatwick and sat smiling in the back seat of a chauffeur-driven black Mercedes with the number plate THAI 1.

On the flight from New York, Mr. Thaksin said: “I didn’t expect this. I was prime minister when I came, and I was jobless on the way back.”

But the signal from the palace, conveyed by General Sondhi, dramatically cuts the likelihood of a comeback.

The monarch is deeply loved by the Thai people — who often refer to “my king” rather than “the king.”

Even among members of Mr. Thaksin’s impoverished rural power base, who have given him unprecedented electoral victories, loyalty to the head of state supersedes any political allegiance. At a news conference earlier, General Sondhi said a new interim civilian prime minister is actively being sought who would be “politically neutral and love democracy with the king as head of state.”

Speaking under a golden army seal at the supreme military headquarters, he said: “We have two weeks. After two weeks, we step out.” But fresh elections would have to wait for a new constitution, which would take a year to finalize, he said, leaving the military effectively in control for the foreseeable future.

General Sondhi insisted that the coup had not been carried out on royal orders.

“We can assure you that this was solely and entirely our decision,” he said.

“We decided on our own, and we took care of it on our own.”

Mr. Thaksin has been widely accused of corruption and abuse of power, leading to huge demonstrations and months of political tension, and General Sondhi said the generals acted to “restore normalcy and harmony.”

He denied that a police general and one of Mr. Thaksin’s closest allies, Deputy Prime Minister Chitchai Wannasathit, had been arrested, saying he had merely been “extended an invitation” and was continuing to enjoy military hospitality.

General Sondhi said the deposed prime minister was welcome back at any time, but he added, “Those who have committed wrongdoings have to be prosecuted according to the law.”

America led adverse international reaction to the coup, urging a quick restoration of democracy and warning that only then would it be willing to move forward on a free trade pact.

“We’re disappointed in the coup. We hope those who mounted it will make good and make good swiftly on their promises to restore democracy,” White House spokesman Tony Snow said.

Britain’s foreign secretary, Margaret Beckett, said: “It’s not for us to say that he [Mr. Thaksin] should be reinstalled. We have called for a return to democratic government.”