ATHENS--Greece slipped back into recession in the first quarter of the year, data from the national statistics service confirmed on Friday, showing how the confrontation between Athens and its creditors has taken a fresh toll on its battered economy.

Gross domestic product shrank 0.2% in the first quarter compared with the last quarter of 2014, according to seasonally adjusted data from Elstat, confirming a preliminary estimate published earlier this month.

That followed a 0.4% contraction in the fourth quarter from the third. Recessions in Europe are commonly defined as two or more consecutive quarterly contractions in GDP.

Greece's economy emerged from a six-year long recession last year, but political uncertainty has been weighing on its economy since late 2014.

According to the final reading of the seasonally adjusted figures, GDP grew by 0.4% on the year from 0.3% previously. But this was a slowdown from a 1.3% annual growth rate in the fourth quarter of 2014.

Greece's snap elections in January, which resulted in the election of a new government led by the radical-left Syriza party, has led to a four-months-long standoff between Athens and its lenders--the rest of the eurozone and the International Monetary Fund--about the conditions of its bailout aid.

Uncertainty about whether Greece's government might default on its debts this summer, potentially leading to the country's exit from the eurozone, has unnerved businesses, consumers and bank depositors. The country now finds itself back in the downturn that has wiped out a quarter of its economic output since 2008.

Greece's government said it is aiming to have an agreement with its international creditors in place by Sunday, but European officials warn that the country is still far from offering sufficient economic overhauls to unlock bailout funds.

Write to Nektaria Stamouli at nektaria.stamouli@wsj.com