Chinese antitrust regulators are investigating a US consortium’s deal for two ports in the Panama Canal zone, reportedly delaying the deal’s closing that was originally set for next week.

President Donald Trump has incorrectly claimed China controls the canal (Panama controls it, although China owns ports on both sides of the crucial maritime passage). Trump has threatened to have the United States once again take control of the canal between the Atlantic and Pacific oceans.

The deal, led by BlackRock, the world’s largest asset manager with an enormous pool of $11.6 trillion in assets, was announced earlier this month and was widely viewed as a way to ease tensions in the region. BlackRock agreed to lead a group that would buy Hong Kong firm CK Hutchison’s controlling interest in 43 other ports around the world, comprising 199 berths in 23 countries.

But China’s State Administration for Market Regulation, the top market regulator, said in answer to a question posed by the state-owned newspaper Ta Kung Pao that it had started an investigation into the deal “in accordance with the law to protect fair competition in the market and safeguard the public interest.” The same statement was reposted on Friday on the website of China’s Hong Kong and Macao Affairs Office.

Following that announcement CK Hutchinson decided that “there will not be an official signing of the two Panama ports deal next week,” according to a report in the South China Morning Post, citing a source close to the Hong Kong firm.

BlackRock did not immediately respond to a request for comment, nor did CK Hutchinson.