U.S. protectionism is undermining agricultural cooperation with China, Beijing's ambassador to Washington said, warning that farmers should not bear the price of the trade war between the world's two largest economies, Reuters reported.

"It goes without saying that protectionism is rampant, casting a shadow over China-U.S. agricultural cooperation," said Xie Feng, according to the transcript of a speech published by the Chinese embassy on Saturday.

Agriculture has emerged as a major point of contention between China and the U.S. as the superpowers are locked in a tariff war launched by President Donald Trump.

China in March slapped levies of up to 15% on $21 billion worth of American agricultural and food products in retaliation for sweeping U.S. tariffs. Washington and Beijing this month extended a trucefor 90 days, staving off triple-digit duties on each other's goods, according to Reuters.