A South Korean conglomerate has been forced by Chinese authorities to suspend a multi-billion-dollar theme park project, as tensions grow over the deployment of a US missile defence system.

The plan by Seoul and Washington to install the Terminal High Altitude Area Defense (THAAD) system in response to threats from North Korea has drawn fire from China, which fears it will undermine its own ballistic capabilities.

Seoul has earmarked a golf course in the southern county of Seongju owned by the Lotte Group, a food, retail and hotel operator that is South Korea's fifth-largest conglomerate, for the THAAD system. It has offered it a plot of military-owned land east of the capital in exchange.

But Lotte has significant business interests in China and has deferred a decision on whether to accept the deal.

Its Chinese projects include a sprawling three-trillion-won ($2.6 billion), 160,000-square-metre complex involving a theme park, shopping malls and a hotel in the northeastern city of Shenyang.

It was forced to stop construction in November after Chinese regulators took issue with some of its safety measures, a group spokeswoman told AFP Wednesday.

The company was not aware of any political motive behind the move, she added.

"Many people talk about potential link with the THAAD deployment over the construction suspension, but we don't know about such things," she said.

Beijing has in recent months slapped a series of measures seen by Seoul as economic retaliation over THAAD, including cancellation of visits by many South Korean celebrities popular in China.

Many South Korean firms have suffered falling sales in China due to tightened customs screening of imports from the country, while Chinese tourist numbers have fallen, according to media reports.

But when US Defense Secretary James Mattis visited Seoul last week he and acting president Hwang Kyo-Ahn vowed to push ahead with the deployment as planned this year.