Vietnam's Department of Overseas Labor (DoLAB) has urged local labor export companies to temporarily stop sending workers to Qatar.
The move come in the wake of a sudden and tense diplomatic crisis that has led some Gulf states to cut diplomatic ties with Qatar and suspend Doha-bound flights.
The blockade will remain in place until the situation in Qatar has new developments, quoted the central labor department as saying.
At the same time, companies that have already sent laborers to Qatar have been asked to monitor the situation closely and provide contact information and support for their workers in Qatar if necessary.
There are currently around 1,800 Vietnamese contract workers in Qatar, mainly working in construction, mechanics and domestic services, according to the labor ministry.
The Arab world's biggest powers cut ties with Qatar on Monday, accusing it of supporting Islamist militants and Iran, and reopening a festering wound two weeks after U.S. President Donald Trump called for Muslim states to fight terrorism, reported Reuters.
Saudi Arabia, Egypt, the United Arab Emirates and Bahrain severed diplomatic relations with Qatar in a coordinated move, while Yemen, Libya's eastern-based government and the Maldives joined later. Transport links have been shut down, triggering supply shortages.
Qatar, a small peninsular nation of 2.5 million people that has a large U.S. military base, has denounced the move saying it is based on lies. It has often been accused of funding Islamists, as has Saudi Arabia.