RIYADH: The United States is studying all available options in how it will confront an attack on Saudi Arabia's oil facilities, U.S. Defence Secretary Mark Esper told Saudi Arabia's crown prince in a phone call on Monday, Saudi state news reported.

In the call to Saudi Crown Prince Mohammed bin Salman, Esper affirmed his country's full support for Saudi Arabia following the attacks, state news agency SPA reported.

In a separate call to Prince Mohammed, Pakistan Prime Minister Imran Khan offered his country's full support and capabilities to the kingdom following the attack, according to SPA.

(Reporting by Stephen Kalin Editing by Chris Reese) ((eric.knecht@thomsonreuters.com; +20 2 2394 8102; Reuters Messaging: eric.knecht.thomsonreuters.com@reuters.net))