Image copyright Reuters Image caption The port is in Fujairah near the tip of the UAE
Work has been halted on a secret £29bn container project in the UAE, officials have said.
The US said it received assurances from the authorities that nothing suspicious was being built in Fujairah, a small Gulf emirate next to Saudi Arabia.
After the US raised questions, China told its ambassador to the UAE to block construction.
Both nations are involved in a war against the Houthi movement in Yemen.
“China never gave permission to construction companies to conduct construction in the port of Fujairah,” Chinese foreign ministry spokesman Geng Shuang said.
Talks about the “secret” project were launched in early May, when Chinese-made ships were imported to the port to assemble port equipment, a local government source was quoted as saying by UAE-based news agency WAM.
“No large-scale construction projects in Fujairah are underway,” said the source, adding that the massive project was aimed at creating a trade hub for “massive business deals”.
Image copyright Reuters Image caption Work has been halted on the largest container project in the UAE after US and Chinese pressure
In Beijing, Geng said China was willing to work with its partners to provide a secure environment in the Gulf.
China regards the Middle East region as strategically important for its oil imports, and the government hopes to improve the “mutual trust” between the two.
In January, a US state department spokeswoman confirmed the security concerns at a news briefing.
Image copyright Reuters Image caption US concerns on the project follow months of fighting in Yemen
“The US asked the UAE for assurances that nothing suspicious was being built in the port of Fujairah, and we also stressed the need for full and complete transparency regarding the work being done there,” the spokeswoman said.
“US officials met twice with the UAE to ensure the commitments were fulfilled.”
A UAE official told WAM the issue was “closed” and that construction work would resume “soon”.