"The name of the capital will be officially written in foreign languages as Krung Thep Maha Nakhon, or Bangkok as before," the statement read.
On Tuesday, the Thai cabinet approved a new register of countries, territories, administrative zones and capitals proposed by the Prime Minister's Office at the recommendation of the ORST.
According to a clarification issued by the office of Thai Prime Minister Prayut Chan-o-cha, the old name Bangkok can be placed in texts in brackets after the new one.
The new name will be officially adopted after a special legal commission reviews the new register, the ORST said.
The new Thai register of toponyms also proposed changing the Thai spelling of the Italian capital of Rome and codifying the transfer of the Myanmar capital from Yangon to Naypyidaw.
The Thai capital has always been called Krung Thep Maha Nakhon in Thai, however this form is also an abridgment since the full name of the city consists of more than 40 separate elements and is the longest name of a capital in the world.