PORTLAND, Maine >> China has failed to lived up to its promise to buy more lobster under a deal that opened the door to an easing of a trade war under former President Donald Trump, Maine’s congressional leaders say.

Maine’s lobster industry was hurt by retaliatory Chinese tariffs in 2018 and failed to see substantial export gains after China committed to buying an additional $200 million in U.S. goods, the delegation contends.

Under the “Phase One Agreement,” China was supposed to increase purchases to 2017 levels but China has bought “almost no lobster above 2017 levels,” according to a letter Thursday by Maine Sen. Angus King, an independent, and Reps. Chellie Pingree and Jared Golden, both Democrats.

They urged U.S. Trade Representative Katherine Tai to “hold China accountable for its purchase commitments.”

Republican Sen. Susan Collins of Maine sent a letter voicing the same concerns and urging “swift and appropriate action.”

Maine’s live lobster sales to China fell in the year after the lobster tariff was imposed in July 2018, and China shifted its lobster purchases to Canadian dealers, industry officials said.

The sparring over lobster came as the U.S. trade representative accused Beijing of failing to carry out market-opening promises made when it joined the World Trade Organization. China rejected the accusations.