The average nightly rate per room fell 24 percent to $85 amid the ban on international flights and social distancing requirements, according to real estate consultancy Savills.

"The second quarter saw the lowest performance due to the lockdown in April and inbounds effectively halted," Matthew Powell, director of Savills Hanoi, said.

Closed borders meant the number of tourists in Hanoi during the first six months fell 65 percent year-on-year to 4.93 million, including 987,000 foreigners.

Even now at least two four-star hotels and eight three-star hotels, with a total of 650 rooms, remain closed in the city, Do Thu Hang, director of advisory services, Savills Hanoi, said.

"Some hotel owners in downtown areas like Hoan Kiem District are still reluctant to reopen due to the plummeting tourist numbers."

This means it would take a longer time for the market to recover, she warned.

Savills said in the second half of this year four hotels with 800 rooms would come into the market. Another 1,550 rooms are set to come in 2011 and 2022.