The US Senate is expected to vote on 21 September on a resolution to block the sale of some $1.15bn-worth of land force equipment to Saudi Arabia.
The measure is not expected to pass with a number of senators aggressively supporting the sale.
The resolution to oppose the sale was introduced by a group of US lawmakers concerned that Saudi-led air strikes had killed civilians in Yemen.
The US State Department approved the sale in August but the deal has to obtain Congress approval before being finalised.
The deal involves more than 130 Abrams battle tanks, 20 armoured recovery vehicles and other equipment, worth a total of about $1.15bn. The US General Dynamics is the main contractor for the deal.
Saudi Arabia leads a 10-country coalition that launched a military offensive in Yemen in March 2015 to control the advance of Houthi rebels, alleged to be supported by Iran, and restore the legitimate government led by President Abd Rabbu Mansour al-Hadi, who fled to Saudi Arabia at the time. Al-Hadi returned to Aden in September 2015.
The 18-month war has resulted in more than 8,000 civilian casualties, nearly 2,800 of whom have lost their lives, as well as 2.4 million displaced people and 21.2 million people in need of humanitarian aid since the military campaign begun.