WASHINGTON (AFP) - The United States on Wednesday backed slow-moving efforts to resolve Honduras' political crisis, despite complaints by ousted President Manuel Zelaya that the process is delaying his reinstatement.

Zelaya, who was overthrown in a June 28 coup but is supposed to be returned to power under a US-brokered agreement, wrote a letter to Secretary of State Hillary Clinton demanding to know whether the United States still supports his reinstatement.

"We believe he should be restored to power," State Department spokesman Ian Kelly told reporters.

Kelly said the United States wanted to see the deal reached at the weekend between Zelaya and the de facto government led by Robert Micheletti, implemented.

The accord calls for the Honduran Congress to decide on Zelaya's reinstatement after consulting the Supreme Court.

"We are committed to the agreement. We're committed to its implementation. We'll continue to assist and support the implementation process, but it's up to the Hondurans to actually carry through," he said.

Kelly would not comment on what the United States would do if the Honduran Congress voted against Zelaya's reinstatement, or if it takes no action before November 27 elections that will choose his successor.

"We'll cross that bridge when we get there," Kelly said.

Zelaya has complained that the de facto government was using the process to stall his reinstatement and run out the clock until the elections.

"Everything that's happening now is laid out in the accord," Kelly said. "So we're going to let the process play out. We're going to support the process. We're going to encourage the people to stay focused on this and make sure that it's implemented."

In Honduras, a four-member commission formed to oversee the accord began work Wednesday. Its members include former Chilean president Ricardo Lagos and US Secretary of Labor Hilda Solis.

Under the deal a national unity government is supposed to take office on Thursday.

Solis said negotiations were "moving" but declined to say whether the unity government could start up before Congress votes on the reinstatement of Zelaya.