Saudi Arabia struggles in persuading Russia to stay longer with the Organization of Petroleum Exporting Countries (OPEC)’s strategy of oil cuts, sources familiar with the topic said, Reuters reported.

Moscow has responded positively to these trials and may agree to stay for more three months. “We can extend for three months when we meet in June and then see if we need to extend later,” an OPEC source said.

The Russian Energy Minister Alexander Novak told his Saudi counterpart Khalid al-Falih during their meeting in Baku that he cannot guarantee the extension will continue to the end of 2019, the sources said.

Saudi Arabia and other OPEC members could be forced to continue the cuts alone if Russia opted not to stay, the OPEC source added.