The four-day International Defence Exhibition and Conference (IDEX) kicked off on Sunday in Abu Dhabi with the United Arab Emirates announcing 21 deals worth more than $1.2bn.
IDEX spokesman Brigadier-General Rashid Mohammed Al Shamsi told reporters the Emirates struck deals with 15 local companies and six international firms to bolster its land and naval forces.
The lion's share came from the $544m purchase of 400 armored personnel carriers from a local manufacturer, the Associated Press reported. Raytheon, a US company based in Waltham, Massachusetts, announced a deal with the UAE navy for missiles to arm its Baynunah-class corvettes.
Many of the other contracts dealt with resupplying ammunition for the UAE, which is taking part in the Saudi-led campaign against Shia rebels and their allies in Yemen, AP said. The war, which has killed more than 10,000 civilians, began in September 2014, and the Gulf Arab nations entered the conflict in March 2015. It shows no signs of ending soon.
Two of the UAE's most-powerful rulers, Abu Dhabi Crown Prince Mohammed bin Zayed Al Nahyan and Dubai's ruler, Sheikh Mohammed bin Rashid Al Maktoum, attended the event.
UAE is also seen as an important regional ally in the US-led coalition's fight against the Islamic State group in Iraq and Syria.
International contracts announced on Sunday included one with French firm Thales Underwater Systems SAS to buy sonars for the navy worth more than $23m, and another with Britain's HESCO Group for defensive fortifications worth more than $24m.
A statement also listed deals with Emirati companies, including one with International Golden Group for ammunition worth around $107m.
The UAE also signed contracts with local firms to supply and install electronic communications systems for the navy, armour mechanisms and monitoring equipment.
IDEX, which runs to Thursday, is one of the largest arms fairs in the Middle East and is held biannually to showcase the latest in defence technologies and innovations.