Huawei and other Chinese tech companies will be subject to tough restrictions from the United States irrespective of any future trade deal, an economist told CNBC Tuesday.

The two largest economies in the world have been at odds over their trade links for about 18 months. Their tit-for-tat tariff dispute escalated in May, when the U.S. took steps to ban Huawei from selling its technology in the U.S. market.

"Even with a phase one trade deal or even a complete trade deal, our conviction is that tougher restrictions from the U.S. on technology will continue," Tao Wang, chief China economist at UBS, told CNBC's Joumanna Bercetche.

Speaking at the UBS European Conference, Wang said that the U.S. decision to ban Huawei was a "catalyst to show that actually the dispute on the trade front has spread to other areas, like technology."

In May, President Donald Trump signed an executive order declaring that the U.S. telecoms sector was experiencing a "national emergency." "Foreign adversaries are increasingly creating and exploiting vulnerabilities in information and communications technology and services," Trump said in the order.