The sale would provide Qatar with roughly ten radars and 34 launchers for Patriot systems designed to knock out incoming missiles, as well as 24 Apache helicopters and Javelin anti-tank missiles.
Qatar was investing in missile defense systems to counter the threat across the Gulf from Iran, which has built up its missile arsenal, officials said.
Qatar's minister of state for defense, Major General Hamad bin Ali al-Attiyah, committed to the sale in a signing ceremony today in Washington after talks with his American counterpart, Chuck Hagel, officials, who spoke on condition of anonymity, told AFP.
"It's a good sign," said a senior defense official, referring to the arms sale and the prospects for the fighter jet bidding.
The United States wants to preserve its role as "the defense provider of choice" for Qatar and other Gulf states, the official said.
The weapons would enhance American's security and diplomatic ties to Qatar, the official said, despite some disagreement over Syria and Qatar's assistance to some rebel groups deemed too radical by Washington.