Hong Kong’s CK Hutchison Holdings has threatened legal action against Danish shipping giant A.P. Moller-Maersk after Panamanian authorities tapped the group to temporarily take over operations of two strategic ports at either end of the Panama Canal.

In a statement on Thursday, CK Hutchison warned A.P. Moller-Maersk that “any steps” the Danish group or its subsidiary takes to operate the ports without its agreement will likely “result in legal recourse.” That’s according to CNBC’s translation of the Chinese statement.

The simmering dispute has become a geopolitical flashpoint between Washington and Beijing, with Panama caught in the crossfires.

After U.S. President Donald Trump alleged last year that China was “running the Panama Canal,” CK Hutchison negotiated a $23 billion deal with a BlackRock-led consortium to sell its non-Chinese port subsidiaries. Beijing swiftly intervened, describing the sale as “kowtowing” to American pressure and stalling the transaction.

Tensions intensified last month when Panama’s Supreme Court ruled that the concession held by a CK Hutchison subsidiary to operate the two ports was “unconstitutional.” The company pushed back, saying it “strongly disagreed” with the ruling and launched arbitration proceedings against Panama.