The announcement came with tensions between Iran and the United States on the rise after Tehran threatened to close the Strait of Hormuz to oil tankers if Washington implements a new raft of sanctions over its nuclear program.

The $29.4 billion deal, which was signed on Saturday in Riyadh, will supply 84 new Boeing F-15SA aircraft, modernize 70 existing planes, and also includes munitions, spare parts, training and maintenance contracts, US officials said.