Technical problems in the US have caused a global backlog of visa applications, the US Consulate in Ho Chi Minh City said Monday.

Countrywide Consular Coordinator David McCawley said in a press release that significant technical problems, including outages, have plagued the Department of State’s visa system and affected global operations since July 19.

Immigrant visa cases are being prioritized.

The department is making progress in fixing the problems, he noted, but asked applicants to delay making final travel arrangements until receiving their visas.

Future applicants are advised to apply for their visas at least several weeks ahead of their planned departure dates.