They will carry out promotions in South Korea and Taiwan, jointly put up booths at major events and showcase popular beach destinations such as Ha Long Bay, Nha Trang and Phu Quoc.

"Vietnam remains one of the most favorite destinations for South Koreans," Park Jong Sun, head of the Korea Tourism Board office in Vietnam told VnExpress International.

"Famous tourist spots such as Ha Long Bay, Hanoi, Da Nang, and Hoi An are heavily favored, particularly by middle-aged tourists."

More than 2.8 million South Koreans visited Vietnam in the first eight months of this year, up 22.5 percent from a year ago, while the number of Taiwanese jumped 27.5 percent to 596,000, according to the Vietnam National Administration of Tourism.

The carriers also pledged to expand code-share cooperation on flights to South Korea and Taiwan and to the U.S. and Canada transiting in Taiwan. Code-share flights to North America would also help the national flag carrier begin its own direct flights to the U.S.

Earlier this month Vietnam Airlines received permission from the U.S. Department of Transportation to begin flights from Hanoi and Ho Chi Minh City to several American destinations such as Los Angeles, San Francisco, New York, Seattle, and Dallas-Fort Worth.

There are currently no nonstop flights between the two countries, and flights from Ho Chi Minh City to San Francisco via South Korea's Incheon take 20.5 hours. The planned direct service to the U.S. West Coast would take only around 13 hours.

Thanks to simplified visa requirements, Vietnam has emerged as a popular travel destination for Americans, who are big spenders, shelling out on average $3,233 per trip, according to a survey released last year by travel insurance comparison site Squaremouth.

May Rut island in Phu Quoc, Kien Giang Province, southern Vietnam.
Photo by Shutterstock/Jimmy Tran.

Americans were among the top arrivals in terms of numbers last year - 687,226 - as Vietnam received a record 15.4 million visitors, a 20 percent increase over 2017.

The country has improved its tourism competitiveness ranking to 63rd out of 140 countries and territories this year in the biennial Travel and Tourism Competitiveness report by the World Economic Forum, jumping four places from 67th in 2017.

Vietnam has been forecast to lead Asia-Pacific destinations in terms of growth over the next five years by the Pacific Asia Travel Association.