The United States has approved the possible sale to Saudi Arabia of up to 153 tanks, hundreds of machine guns and other military gear in a deal worth $1.15 billion, the Pentagon said Tuesday.

The announcement coincided with news that Saudi-led coalition warplanes had resumed air strikes on Yemen's capital for the first time in three months, killing 14 people and shutting the airport after UN-brokered talks were suspended.

State Department spokeswoman Elizabeth Trudeau said she was "very concerned" by Tuesday's reports of casualties in Yemen, but she did not directly comment when asked if the State Department worried US weapons being sent to Saudi Arabia could be used against civilians.

"We regularly talk to our partners and our allies around the world. You know, civilian casualties are obviously of grave concern to us," she said.

According to the Defense Security Cooperation Agency (DSCA), Riyadh had requested the possible purchase of up to 133 American M1A1/A2 Abrams tanks that would be configured to Saudi needs, plus another 20 to replace damaged tanks in their fleet.

Additionally, the deal would include 153 .50-caliber machine guns, 266 7.62mm M240 machine guns, smoke grenade launchers, armored recovery vehicles and a range of other hardware.

The US State Department has approved the "possible" sale and notified Congress on Monday, the DSCA said.

"This proposed sale will contribute to the foreign policy and national security of the United States by helping to improve the security of a strategic regional partner which has been and continues to be a leading contributor of political stability and economic progress in the Middle East," the DSCA said in a statement.

"The addition of these tanks and recovery vehicles to the (Saudi military's) inventory will enhance Saudi Arabia's ability to support its soldiers in the field and to defend the Kingdom's borders."

The Pentagon announcement made no mention of the conflict in Yemen, where the Saudi coalition intervened in March last year after Shiite Huthi rebels and allied forces loyal to former president Ali Abdullah Saleh overran Sanaa.

Saudi Arabia also forms part of the US-led coalition fighting Islamic State jihadists in Syria and Iraq.