In early September 2016, following a meeting between Russian president Vladimir Putin and Saudi deputy crown prince Mohammed bin Salman on the sidelines of the G20 summit, Saudi Arabia, a leading OPEC member, and non-OPEC Russia agreed to cooperate in world oil markets to tackle a global glut, saying they could limit output in the future and signing a joint statement to this effect. Later that year, Russia agreed to join OPEC nations′ commitment to reduce oil output, with cuts taking effect from 1 January 2017 to last for six months; Russian president Vladimir Putin and Saudi deputy crown prince Mohammed bin Salman, along with Iran's supreme leader Ayatollah Ali Khamenei, were said to have played a key role in having OPEC rivals Iran and Saudi Arabia set aside differences to make the organization's first deal with non-OPEC Russia in 15 years possible. In April 2017, deputy crown prince Mohammed bin Salman told "The Washington Post" that the Saudis had been “coordinating [their] oil policies recently” with Moscow in order to convince Russia that Riyadh was a better bet for them than Tehran, the main goal being ″not to have Russia place all its cards in the region behind Iran″.