BEIJING (AP) — China's yuan has fallen below the politically sensitive level of seven to the U.S. dollar, possibly adding to trade tension with Washington.

The tightly controlled currency weakened to 7.0177 to the dollar on Monday following President Donald Trump's latest threat of tariff hikes on Chinese goods.

The yuan's weakness is among a series of U.S. complaints that are fueling tensions with Washington. American officials complain a weak yuan makes China's exports too inexpensive, hurting foreign competitors and swelling Beijing's trade surplus.

The level of seven yuan to the dollar has no economic significance, but could revive U.S. attention to the exchange rate.

Trump's tariff hikes in a fight over China's trade surplus and technology ambitions have put downward pressure on the yuan by fueling fears economic growth might weaken.