After trying to placate Donald Trump for more than a year only to face tariffs on virtually all of its shipments to the United States, China is signaling it's ready to play hardball.

In a stark escalation of the trade war that has roiled financial markets and weighed on economic growth worldwide, Beijing let the yuan tumble Monday to the weakest level in more than a decade and asked state-owned companies to suspend imports of U.S. agricultural products.

The moves emerged within days of Trump's threat to impose additional tariffs on China and struck at the heart of two of the U.S. president's fiercest criticisms — that Beijing manages its currency unfairly to help exporters and has failed to keep promises to buy more U.S. crops after a trade truce in June.