Beijing "will take countermeasures in a resolute and reciprocal manner" if any country sought such deals, a ministry spokesperson said

Beijing's expanding influence on the world's oceans is a challenge to Washington's efforts to protect its interests.

The tariff actions, which could upend nearly $2.2 trillion in two-way annual US trade went live at 12:01 am EST (0501 GMT)

Beijing will impose an additional 15% tariff on US chicken, wheat, corn and cotton

All eyes will also be on possible stimulus to boost domestic demand, sorely needed to counter a potential drop in tariff-sensitive exports.

China dominates global supply chains for rare metals.

Beijing slaps 15% levy on US LNG, coal; 10% on crude, farm equipment

Trump has also hit China with a 10-percent tariff in addition to levies already in place.