China on Monday let the yuan tumble beyond the key 7-per-dollar level for the first time in more than a decade, in a sign Beijing might be willing to tolerate further currency weakness in the face of an escalating trade row with the United States.

The sharp 1.4% drop in the yuan came after the People's Bank of China (PBOC) set the daily mid-point of the currency's trading band at 6.9225 per dollar, its weakest level since December 2018.

“Today’s fixing was the last line in the sand,” said Ken Cheung, senior Asian FX strategist at Mizuho Bank in Hong Kong. “The PBOC has fully given the green light to yuan depreciation”

The shakeout in the yuan comes days after U.S. President Donald Trump stunned financial markets by vowing to impose 10% tariffs on the remaining $300 billion of Chinese imports from Sept. 1, abruptly breaking a brief month-long ceasefire in the bruising trade war.

With the escalating trade war giving Beijing fewer reasons to maintain yuan stability, analysts said they expect the currency to continue to weaken.