A Greek and a tangled EU flag flutter atop Greece's Financial Ministry in Athens, Greece June 24, 2016 after Britain voted to leave the European Union in the Brexit referendum. REUTERS/Yannis Behrakis

BRUSSELS (Reuters) - Greece’s primary surplus was 4.2 percent of gross domestic product (GDP) last year, significantly above the target set for Athens under its bailout program, the European Commission said on Monday.

“The mission is returning to Athens today with the objective of concluding a sub-level agreement as soon as possible on the basis of the understanding of Greeks of the Eurogroup in Valletta,” European Commission spokesman Margaritis Schinas told a news conference, adding that talks were expected to take several days.

Schinas said the 4.2 percent primary surplus - a measure that excludes interest payments - was well above the program target of 0.5 percent for 2016 and even above the level of 2.5 percent set for 2018.

“This confirms the trend which we at the Commission have been reporting for a while,” he said.