Iran’s navy conducted military exercises with Russia on Thursday as the country’s foreign minister spoke late Wednesday with his Saudi counterpart about ongoing nuclear talks, amid growing signs of American frustration with the negotiations.

What happened: The joint exercise included a simulation in which a ship was retaken after a hijacking. Naval forces from the Iranian Army and the Islamic Revolutionary Guard Corps took part alongside their Russian counterparts, Iran’s state-run Press TV reported.

Iran deployed SH-3 and Bell 412 helicopters, F-4 fighter jets, the Alvand destroyer command ship, and Neyzeh and Khanjar missile-launching vessels in the exercise, among other assets. Russia sent the Bravyi destroyer, according to the outlet.

Asked Wednesday whether the drill was linked to US-Iran tensions, Russian presidential spokesperson Dmitry Peskov told reporters the exercise had been “agreed upon in advance.” Iran’s state-run Press TV reported that the drills took place amid “heightened regional tensions and repeated US threats to attack Iran if it does not accept nuclear demands.”