Russia has signed an agreement to sell Vietnam a dozen Sukhoi-30 multirole combat aircraft for more than $600 million (450 million euros), Russian news agency Interfax reported Tuesday.

The fighters which can travel twice the speed of sound will be delivered in 2014 and 2015 under the deal signed last week, according to a military-diplomatic source cited by Interfax.

The purchase is the third by Vietnam of Sukhoi fighters.