WASHINGTON, March 29 (Xinhua) -- The United States has decided to transfer its current immigrant visa processing business for Cuban nationals to the U.S. embassy in Georgetown, Guyana, the U.S. State Department said on Thursday.

In an announcement, the department said that the processing business included visa applications and scheduling of immigrant visa interviews.

Immigrant visa interview appointments for Cuban nationals have been scheduled at the U.S. embassy in Bogota since January due to a drawdown in staffing in Cuba, it said.

Guyana will be the primary site for processing immigrant visa applications for Cubans since April 1 and no applicants should make travel plans until they have a scheduled visa interview appointment.

The first interviews will take place in June, said the State Department.

Cubans do not need a visa to travel to Guyana. As before, Cuban applicants for routine non-immigrant visas may apply at any U.S. embassy or consulate outside Cuba, it said.

Explaining the picking of Guyana, the department said it has considered a number of factors including availability of flights, visa requirements, space to accommodate additional applicant files and availability of staff.

The department said on March 2 that the U.S. embassy in the Cuban capital Havana is to operate with the minimum personnel permanently, due to the reported health attacks against U.S. employees.

However, it admitted that it still did "not have definitive answers on the source or cause of the attacks, and an investigation into the attacks is ongoing."

Although the United States has not formally accused Cuba of carrying out the attacks, the unexplained physical afflictions suffered by 24 U.S. embassy personnel in Cuba led to a partial closure of the embassy and suspension of granting visas to the Cubans.

Cuba denied the accusations, saying the investigation to resolve the matter was still in progress and "effective cooperation" of the U.S. authorities was essential.