Cambodian Prime Minister Hun Sen on Tuesday denied that he deterred the proceedings at the United Nations-backed Khmer Rouge tribunal, saying that he also expressed concern over the tribunal's slow work.

The premier said that he expressed his concern while meeting separately with Ambassador Jean-Francois Cautain, head of EU Delegation to Cambodia, and British Ambassador to Cambodia Mark Gooding.

"For the trial of Khmer Rouge leaders, we expressed our joint concern while we met separately a few weeks ago because, firstly, the court is facing budget shortage and secondly, the accused are old, and recently, Ieng Sary died. If the trial remains delayed, this issue will...," Hun Sen said during the inauguration of the National Council on Green Growth.

The premier said that his remarks were to respond to the comments by Brad Adams, director of Asia programs at Human Rights Watch, who said that Hun Sen is the person hampering the proceedings at the Extraordinary Chambers in the Courts of Cambodia (ECCC).

"For this tribunal, the rights and power are under the tribunal, the slow or fast proceedings are up to the tribunal, it is not dependent on me," Hun Sen said. "He should not pin the blame on me. "

Established in 2005, the UN-backed tribunal is seeking justice for an estimated 2 million people who died during the Democratic Kampuchea, or known as Khmer Rouge regime, from 1975 to 1979. As of last year, the hybrid court had spent about 175 million US dollars for its operations.

To date, the tribunal has achieved only one conviction, sentencing ex-chief of Tuol Sleng prison Kaing Guek Eav to life in prison for overseeing the deaths of around 15,000 people during the regime.

Last Thursday, ex-Khmer Rouge Foreign Minister Ieng Sary, who was one of the three senior Khmer Rouge leaders, being tried by the tribunal, died at the age of 87 due to illness.

The two ailing leaders facing trial are Nuon Chea, 86, also known as "Brother Number 2," former deputy secretary of the Communist Party of Kampuchea, and Khieu Samphan, 81, the regime's former head of state.

They face a series of charges, including crimes against humanity, genocide, homicide, torture, and religious persecution over the deaths of an estimated 2 million people from starvation, overwork, torture, execution, and massacre during the Khmer Rouge regime from 1975 to 1979, according to the court's document.

The court is now facing another setback due to the fact that there is no budget to pay salaries for about 280 Cambodian staff. On March 4, more than 20 Cambodian staff in the translation and interpretation department went on strike to demand their unpaid salaries, forcing the court to temporarily close.