Deliveries of S-300 missile defense systems to Venezuela have been delayed, but will go ahead, an official at Rosoboronexport, Russia’s state-owned arms export monopoly, said on Tuesday.

In November, Venezuelan President Hugo Chavez said that Russia had agreed to lend his country over $4 billion to buy weapons.

“There is a contract with Venezuela but it’s not yet being implemented,” Rosoboronexport special programs director Nikolai Dimidyuk told reporters.

“Venezuela has rescheduled the dates several times, but now we have agreed on a timeframe for the deliveries,” he added.

Venezuela is one of the biggest buyers of Russian arms.