Greek Prime Minister Alexis Tsipras said Saturday that differences between the country’s international lenders over its pension reform plans are delaying the first review of its latest financial bailout. Reforming Greece’s ailing pension system is a prerequisite for the conclusion of the review, which is expected to open the way for debt relief talks.

The government has faced widespread demonstrations over its reform plans, however, as austerity-weary Greeks push back against yet more cuts to the country’s welfare system.

“There are differences among the lenders on Greece’s pension reform that are delaying the whole process,” Tsipras said without elaborating in an interview in the newspaper Sunday Avgi released Saturday. He added that the negotiations for the review are in the final stage and repeated he is willing to increase contributions to the pension funds to save pensioners’ income.

Friday, thousands of farmers from all over the country rallied in Athens in their first major demonstration in the capital. The pension reforms would triple their pension contributions.

The International’s Monetary Fund director for Europe, Poul Thomsen, said Friday that Greece will need to implement extra measures worth about 9 billion euros ($10.13 billion) to meet its fiscal targets by 2018. “We cannot see how Greece can do so without major savings on pensions,” Thomsen said.

Tsipras was elected last year on a promise to end austerity. But he was forced to accept a third bailout for the country in July and is struggling to conclude the bailout review and convince angry Greeks that after six years of belt-tightening the latest measures are worth it.

Greece is being asked to cut pension spending by 1 percent of gross domestic product this year. Athens has refused to cut pensions as part of its bailout, and says it will increase social security contributions instead.

“We have presented our proposals on the pension reform, and informed the institutions [lenders] at the beginning of January. So far, we don’t have their official position,” Tsipras said.