Thailand's navy has voted in favour of buying three Chinese submarines worth US$1 billion, an official said Thursday, the kingdom's first such vessels in decades if the purchase is approved by the cabinet.

The country last operated submarines in its waters 50 years ago and wants the new high-tech vessels as a "deterrent", said Thailand's navy chief, without elaborating on the nature of threats faced by the junta-ruled nation.

"Fourteen of the 17-strong submarine selection committee has voted to buy three submarines from China," navy chief Kraisorn Chansuvanich told reporters in Bangkok.

It is unclear when the cabinet will meet to consider the navy's decision but if approved the submarines would come into operation within seven years.

"These are weapons for our future security. They will be used as a deterrent," he said.

For more than a decade Thai forces have battled against ethnic Malay Muslim insurgents calling for greater autonomy in the country's southernmost provinces.

Thailand was also involved in a series of deadly border clashes with Cambodia in 2011.

But unlike several of its Southeast Asian neighbours, Thailand has not been embroiled in a bitter and longstanding maritime dispute with regional giant China in the South China Sea, which Beijing claims almost in its entirety.

The proposed 36 billion baht ($1 billion) Thai-Sino submarine deal would see China build three brand new submarines fitted with arms and also include training for Thai officials, Kraisorn said.

Russia, France, Sweden, Germany and South Korea had also pitched to build the vessels but the Chinese offer was the best as it included arms for all three submarines, he added.