Panama’s foreign minister asked China to “respect” his country’s sovereignty, accusing Beijing of detaining Panamanian ships in retaliation for legal action against a Hong Kong-listed firm.

The countries have been at odds since Panama — under pressure from the Trump administration — canceled CK Hutchison’s contract to operate two ports along the Panama Canal; Washington had earlier argued the ports gave Beijing control over a passageway that’s vital to the US economy. Since the start of his second term, US President Donald Trump has pushed Latin American nations to limit ties with Beijing.

China has in recent years become the biggest trading partner for several countries in the region, meaning any pivot could have huge economic impacts.