ATHENS (Reuters) - Greece's primary surplus budget target beyond 2018 should be lowered to 1.5-2 percent of gross domestic product, the country's Deputy Finance Minister George Chouliarakis said on Wednesday.

Under its third international bailout, Athens has agreed to achieve a primary budget surplus of 3.5 percent of GDP in 2018, although the International Monetary Fund and some Greek officials have argued that the target is not realistic.

"A commitment is a commitment ... and we have to honor this commitment if we want to restore and enhance credibility," said Chouliarakis, referring to the current primary surplus targets set in its bailout up to 2018.

"But we need reconsider the level of primary surplus targets beyond the lifetime of the program, after 2018. Our preference is for a significantly lower primary fiscal target beyond 2018 in the range of 1.5 to 2 percent," he said during an Economist conference.

(Reporting by Renee Maltezou and Lefteris Papadimas)