People wait outside the United States embassy in Beijingon Monday for visa applications. A computer problem that occurred in the US visa application system on July 19 has significantly reduced the embassy's capacity for handling visa applications. (Wang Jing / China Daily)

Delays in issuing visas for the United States are likely to persist as the computer problems causing them have not yet been resolved, Nolan Barkhouse, spokesman for the US embassy in Beijing, said on Monday.

"Our recordssystem has been experiencing significant performance problems, including outages, since July 19," he said.

Barkhouse said the visa service returned to online working last Wednesday, but it is still operating at a significantly reduced capacity.

"The delay will continue until the document backlog is cleared," he said.

The problems affecting the US State Department's central visa and passport database mean applicants around the world face delays.

There have been fears that Chinese students planning to attend college in the United States will not be able to obtain visas in time for the start of term. However, an overseas study adviser says they may not be affected.

"If the system can return to full operation by early August, then I think there's still time for Chinese students to apply for and get their visas," said Wang Jing, director of the US section at Chivast Education International, an overseas study consultancy in Beijing.

The consultancy helps Chinese students to apply for places at foreign universities and to obtain visas.

Wang said 2,300 Chinese students due to start their studies in the US in August are obtaining their visas through Chivast. By Monday, only 68 had not yet started the application process.

"The possible reason why these students apply so late may be that they receive admission from their universities late, or for other personal reasons," said Wang.

"At present, students still have a chance to make it for the start of the semester if the system returns to normal and the embassy processes the applications quickly."

Barkhouse said the computer problems were not the result of malicious actions or hacking, but the exact cause is not yet known.

"We are working urgently to correct the problem and expect the system to be fully operational again soon," he added.

"The service will continue to be disrupted until the system is fully functional," he said.