The United Arab Emirates' ambassador to Washington said he was confident the sale of F-35 jets to his country would go through after a review by President Joe Biden's administration of some pending arms sales to US allies. During Donald Trump's last day in office, the UAE signed agreements to buy up to 50 F-35 jets, 18 armed drones and other defence equipment in a deal worth $23 billion. "We did everything by the book and they will discover that once the review is complete and it will proceed," Ambassador Yousef Al Otaiba told an online Washington Institute forum on Monday, describing the review as "pro forma". Last month, a US State Department official said Mr Biden's administration was temporarily pausing the implementation of some pending arms sales to US allies to review them. "Everything is still proceeding while undergoing a review at the same time. I am confident it will end up in the right place," Mr Otaiba said. "If you are going to have less of a presence and less involvement in the Middle East you can't at the same time take tools away from your partners who are expected to do more," he said. The F-35 arose from the US "joint strike fighter" programme, which called for a multi-purpose stealth combat aircraft capable of vertical take-off. This followed decades of research into aircraft with a small radar signature, arising from the need to launch strike missions deep into enemy territory, where US adversaries were using increasingly powerful radar systems to detect conventional planes. The F-35 is also considered unique by aviation analysts because of its ability to network with other aircraft and military systems using powerful onboard computers, giving pilots a highly detailed overview of real-time threats on the battlefield.