The tribunal has been beleaguered by political and financial considerations since its establishment in 2006. It spent $141.1 million through 2011, and so far has completed only one trial, finding the head of a Khmer Rouge torture center guilty of crimes against humanity and other offenses.
The tribunal said in a statement that it would provide funds covering January through April this year, but did not specify how much would be given. Foreign and Cambodian personnel are paid under separate budgets.
The tribunal is tasked with seeking justice for atrocities committed by the Khmer Rouge during its 1975-79 reign of terror, when an estimated 1.7 million Cambodians died from forced labor, starvation, medical neglect and execution.
In mid-2011 it began trying four former top members of the Khmer Rouge for genocide. Last year, one defendant, former social affairs minister Ieng Thirith, was ruled mentally incompetent to stand trial, and was freed from custody. Her husband and co-defendant, Ieng Sary, the Khmer Rouge's foreign minister, died earlier this month.
The two remaining defendants in the current trial are former head of state Khieu Samphan, 81, and the group's chief ideologist, Nuon Chea, 86.
The defendants' age and poor health have raised concerns that they may not live long enough to hear a verdict. The tribunal ruled Friday that a medical exam determined that Nuon Chea was fit to stand trial, but expressed concern about the state of his health.
Tribunal officials are seeking to prosecute other former Khmer Rouge leaders, but Cambodian Prime Minister Hun Sen has warned that more trials will "not be allowed," claiming they could cause unrest. Many people in Cambodia's government, including Hun Sen himself, are former Khmer Rouge officials.
The current trial has been stalled for weeks due to the financial problems as well as the ill health of the defendants, who have been repeatedly hospitalized.
Translators for the tribunal went on strike in early March over their pay complaint. They agreed to resume work after being paid their wages for December.
Tribunal spokesman Neth Pheaktra said Saturday that the government, which is responsible for paying the Cambodian staff, and the United Nations were continuing negotiations about the shortfall of funds and how to pay salaries for the rest of the year.
Foreign aid donors have provided millions of dollars for the tribunal, but most of it is earmarked for the international staff.