WASHINGTON (Reuters) - The US Defense Department said on Thursday it would send 200 troops and Patriot missiles to Saudi Arabia to help defend the kingdom after last month's attacks on oil facilities in which Washington blamed Iran.

"This deployment will strengthen the Kingdom's air and missile defense against vital military and civilian infrastructure," Pentagon spokesman Jonathan Hoffman said.

"It is important to note that these measures demonstrate our commitment to our regional partners and to the security and stability of the Middle East."

Defense Minister Mark Esper announced that the equipment included one Patriot battery, four radar systems, and nearly 200 military support personnel.

Relations between Tehran and Washington have deteriorated since Trump decided to withdraw from the 2015 nuclear deal between Iran and major powers and reimpose sanctions on the Islamic Republic.

This will be the first such deployment since 2003, when US forces withdrew from Saudi Arabia after 12 years in the kingdom, from the occupation of Kuwait to the invasion of Iraq in 2003.

The United States announced last Friday its intention to send military reinforcements to the Gulf after the attacks on Aramco, in a decision hastily welcomed by Riyadh.