China said on Monday its overall trade surplus was $41.65 billion last month, significantly more than expected as the trade impasse between Washington and Beijing drags on.

Economists polled by Reuters had expected China to post an overall trade surplus of $20.5 billion in May.

The larger trade surplus came as the country's dollar-denominated exports surprisingly increased last month, while imports came in worse than expected. China's General Administration of Customs said on Monday that exports in May inched up 1.1% year-on-year, while imports fell 8.5% during the same period.

Economists in the Reuters poll had forecast both exports and imports to fall 3.8% year-on-year in May.

In April, China's overall trade surplus in April was $13.8 billion, far below the projected $35 billion. That's partly due to an unexpected rise of 4% in imports, and a surprise fall of 2.7% in exports for the month.