Though Sri Lanka allowed fully vaccinated travelers to visit the country from Thursday with only one-day in quarantine, those with a travel history in Vietnam spanning the past 14 days are still banned from entering until further notice.
India, South Africa, Angola, Botswana, Lesotho, Mozambique, Namibia, Swaziland, Zambia and Zimbabwe face the same extended entry ban.
Sri Lanka, which has reported nearly 270,000 infections and 3,391 deaths, banned entry for arrivals from Vietnam starting June 1.
The Sultanate of Oman has also decided to extend its suspension of entry for arrivals from Vietnam from Friday until further notice. Omani citizens, diplomats, health staff, and their families are exempt from the ban and will be subject to entry procedures adopted by the Sultanate.
Oman, which added Vietnam to its travel ban list last month, has recorded over 281,000 infections and 3,371 deaths.
The highly transmissible Delta variant, first identified in India, has become the most prevalent in many countries, including Vietnam where most new cases are linked to it.
Vietnam has recorded over 21,000 community infections in its ongoing Covid-19 wave, which started on April 27 and has been the nation's most challenging so far.