US Deputy Secretary of State John Negroponte tours Tuol Sleng prison Tuesday with Youk Chhang, director of the Documentation Center of Cambodia.

The US is ready to commit $1.8 million to the UN side of the Khmer Rouge tribunal, a top US official said Tuesday, but he warned that the courts will have to continue to tackle corruption issues that have plagued them from the beginning.

The money would be US's first direct contribution to the tribunal, and the announcement came after a day of talks between the Cambodian government and US Deputy Secretary of State John Negroponte, who holds the second-highest position in the State Department.

"We expect to be active among donors to the tribunal to ensure that it continues to improve its management and address the issue of corruption," Negroponte said, adding that the US would have a voice in the proceedings and would "spare no effort" to ensure money was spent properly.

The US played an active role in the negotiating the hybrid tribunal with Cambodia and the United Nations, but officials had said until Tuesday they would not fund a substandard tribunal.

The tribunal has detained five former leaders of the Khmer Rouge regime, and is set for the first trial of any leader in 30 years, Tuol Sleng prison chief Duch. 

But the tribunal has been hounded by allegations of mismanagement and corruption, and the Cambodian side has seen at least $300,000 in donor funding frozen, following fresh allegations of kickbacks in June.

Negroponte acknowledged there had been mismanagement in the courts, "but not to the level that justified withholding any contribution."

"I think there's generally a consensus that this is a good time to move forward," he said.

Tribunal spokesman Reach Sambath welcomed the US contribution, saying that a US donation to the UN side will be the second from international donors, following a $750,000 contribution from the French earlier this year.

The tribunal needs $50 million added to its entire budget by the end of 2009 to continue its operations. Of that, the Cambodian side will need $10 million.