Speaking to reporters on Monday about the Cat Linh-Ha Dong line, also the country’s first metro service, Hue said the city has been training personnel, and the longer the work is delayed, the more difficult it would be to retain them.

Officials said earlier that 28 percent of the nearly 1,000 people who were trained quit last year following repeated delays.

Hue said city officials are working with the Ministry of Transport to address the problems faced by the project.

One of the main challenges now is that many Chinese experts working on it have not been able to enter Vietnam due to the coronavirus outbreak. Of the 150 needed for the remaining work, 26 are set to arrive on June 12. It is unclear when the rest will come.

A safety evaluation is needed before commercial operation can begin. Again, the experts who are to do the evaluation, from French firm Apave-Certifer-Tricc, have been unable to enter Vietnam.

The Cat Linh-Ha Dong Metro Section runs 13 kilometers from downtown Dong Da District to Yen Nghia in the southwestern district of Ha Dong. It is one of eight metro routes planned for the city.

Construction began in October 2011 and was originally scheduled for completion in 2013. But several hurdles, including loan disbursement issues with China that were only resolved in December 2017, stalled it for years.

Its cost has doubled to VND18 trillion ($775 million), with 77 percent of it coming from official development assistance loans from China.