On Monday, the Ministry of Transport's (MoT) deputy minister, Nguyen Hong Truong, told reporters the taxi app service was illegal.

The following day, however, MoT Minister Dinh La Thang said the service should be legalised.

Uber launched its taxi services officially in Vietnam on 31 July.

The San Francisco-based firm says it operates in 250 cities and 50 countries around the world. However, it has been facing opposition in several markets.

It has also been criticised for what have been described as aggressive business practices in cities around the world.

Most recently, Uber has been declared illegal in Thailand and has clashed with Indian authorities over the way customers pay fares.

It said that rules in India which require credit-card payments to use a two-step authentication process were "antiquated".

However, in a statement translated from Vietnamese, Mr Dinh La Thang questioned why the taxi app service should not be allowed in his country.

"Obviously this type of business is priced lower than the regular taxi, and with low cost, people will find it more beneficial to use," he said.

"Around the world, people have applied this before, so why would we not?" he asked.

"If this type of business software by Uber has not been defined in the legal documents, decrees, circulars, instructions, it's our responsibility to modify and legalise it."

He said the ministry needed to find a way that was easier to manage the service, "but also more convenient for the population".

Uber's communications lead for South Asia, Karun Arya, said the firm's service had proven popular since launching first in Ho Chi Minh City, then in Hanoi.

"We've had a tremendous response in Vietnam - it's far exceeded any of our expectations," he told the BBC.

BBC News - December 3, 2014