Trump cited the fentanyl issue as the reason for imposing a 10% tariff on all Chinese imports in early February, on top of any existing duties. He doubled that to 20% earlier this month. He also has cited fentanyl, along with other reasons, for imposing tariffs on Canada and Mexico.

China’s exports to developing markets have soared, opening indirect routes to the U.S. market that officials in Beijing worry may be closed under pressure from President Trump.

Potential plans range from partnering more closely with Panamanian security forces to a less likely option of U.S. troops' seizing the canal by force, U.S. officials told NBC News.

Chinese authorities summoned Walmart executives this week over reports it asked suppliers to bear rising costs incurred by increased US tariffs. Bloomberg's Emily Cohn discussed what's at stake on Bloomberg .