Many victims were disappointed with the UN-backed Khmer Rouge tribunal's sentencing of prison chief Duch last week.
Cambodian officials maintain that the land, west of Preah Vihear temple, does not belong to Thailand.
Cambodia has had diplomatic relations with Iran since 1992, but it communicates with the country through its embassy in Hanoi.
International donors have praised the conclusion of the Khmer Rouge tribunal in the case against prison chief Duch.
The government has been tearing down these kinds of reservoirs since late June, under the new Tonle Sap Authority.
Kem Sokha, president of the Human Rights Party, said in an interview with VOA last week that his party faces repression.
The author of a Khmer Rouge memoir who now lives in the US is raising funds to help education in Cambodia.
Authorities say they are concerned infected pigs are being smuggled in from Thailand and Vietnam.
Hun Sen said the courts had made an independent decision free of political influence.
Duch, whose real name is Kaing Kek Iev, faces the prospect of release at the age of 86.
Following last week's verdict of Duch, 24 of 90 victims who claimed they lost loved ones in his torture center were dismissed.
Trade volume between the two increased more than 120 percent in the first quarter of the year compared to the same period last year.