AUGUSTA, Maine — Data shows Maine shipped $2.8 billion worth of goods last year, but international trade disputes have experts wondering "what could have been."

The Portland Press Herald reports Maine exports increased 4 percent compared to 2017, but it was less than in 2016.

The state's top exports were lobster and fish, machinery and fuel.

Maine International Trade Center President Wade Merritt says export values grew by 9 percent in the first half of last year, but the second half of the year was flat.

President Donald Trump's administration imposed a tariff on imported steel and aluminum in March 2018, and countries such as China and Canada responded with their own tariff hikes.

Merritt says there was overall uncertainty in the market last year, and the trade disputes "certainly didn't help."