April 14 (Reuters) - Greek Prime Minister Alexis Tsipras on Thursday urged Athens's creditors to swiftly conclude a review on its progress on economic reforms, saying he failed to understand why the International Monetary Fund wanted to shift the burden onto the relatively poor.
The review of Greece's progress on the terms of the bailout agreed in July has dragged on for months, largely because of differences among its lenders over the country's economic progress and resistance in Athens to unpopular measures.
Talks in Athens were unexpectedly interrupted on Tuesday. Greece said they will resume immediately after the IMF's spring meetings in Washington, which start Friday and end on Sunday.
"Greece fails to understand why the IMF insists in changing the design of the reforms in a way that leaves their yield and simplicity intact, but makes the reform significantly less progressive, shifting a considerable share of the burden on to the relatively poor," Tsipras wrote in an op-ed for London's Financial Times published on its web site on Thursday.
"....Delaying the conclusion of the first review of the ESM programme by stubbornly insisting to ignore the letter and the spirit of the agreement does not serve the principles on which Europe has been thriving."
Greek reforms and debt relief are expected to be discussed on the sidelines of the IMF meetings.
The IMF, which projects that Athens will miss its bailout target of a 3.5 percent of GDP primary surplus in 2018, is expected to decide whether to co-finance Greece's third bailout after the review, and in light of how much debt relief it receives.
Athens signed up to a new bailout worth up to 86 billion euros ($98 billion) last year, its third international rescue package since 2010.
Tsipras, a leftist who was first elected on pledges to end austerity but who then caved in when it appeared a financial meltdown could leave the country out of the euro zone, said Greece was "laying the foundations for a sustainable and inclusive recovery".
The IMF, European Commission, European Central Bank and the European Stability Mechanism make up the country's lenders.
IMF Managing Director Christine Lagarde said on Thursday the Fund would not abandon the institutions underpinning Greece's bailout, but its participation could vary depending on how the bailout is restructured. (Reporting by Michele Kambas and Renee Maltezou, editing by Larry King)