RIYADH, Feb 2 (Reuters) - Saudi Finance Minister Mohammed al-Jadaan said a government efficiency office created last year to review state projects has saved the kingdom 80 billion riyals ($21 billion) on costs, according to the ministry's official Twitter account.

Jadaan expects increased savings this year and in future years to have a positive impact on the kingdom's finances and the ministry has set up a mechanism to reimburse contractors within 60 days, as promised in December, he said.

(Reporting by Katie Paul; Editing by Louise Ireland) ((Katie.Paul@thomsonreuters.com;))