More than a thousand foreign tourists arrived in Bangkok on Monday, the first wave of travellers to the Thai capital in 18 months, as part of a quarantine waiver for visitors vaccinated against COVID-19.

There were 1,534 foreign arrivals and 890 Thais on 40 international flights on the opening day on Monday, senior health official Kiattiphum Wongraijit said.

The waiver covers more than 60 countries, including the United States and China, plus several places in Europe, from where some were escaping the winter blues.

"Right now, in Europe as you know it’s quite cold, so we decided to go come here," said German tourist, Simon Raithel, among the first arrivals.

Thailand, one of the Asia-Pacific's most popular tourist destinations, has enforced strict entry curbs that were criticised in the travel industry for being too onerous and economically damaging.

More than 3 million Thai tourism-dependent jobs and an estimated $50 billion a year in revenue have been lost.

Before the pandemic, tourism accounted for about 12% of Thai GDP, with one survey ranking Bangkok as the world's most visited city.

Thailand tested the waters with the reopening of the island of Phuket, but the pilot scheme had mixed results, drawing just 1% of its monthly pre-pandemic level when it started in July.

Under the new national programme, visitors must await a negative COVID-19 test on arrival then can travel freely the following day.

"It is much easier," said Marguerite Jeason from France. "Before at first it was 14 nights."

Airlines have rushed to ready the country for the hoped influx of visitors, bringing jets back from hibernation.

Still, the pickup is expected to be relatively slow, with 180,000 foreign arrivals anticipated this year and 7 million next year, compared with some 40 million in 2019.