The current trade impasse between the world's two largest economies won't be resolved anytime soon, according to a former assistant U.S. trade representative for China affairs.

Systemic differences on policies were the biggest obstacle to a trade deal, said Timothy Stratford, who is currently a managing partner at law firm Covington & Burling. The issues at stake are so complex so "we can expect that there's going to be a deadlock for some time," he told CNBC at the World Economic Forum in Tianjin on Wednesday.

A long-term China resident, Stratford resigned from his government post in 2010. During his more than 20 years of working experience in China, he was also minister-counselor for economic affairs at the U.S. embassy in Beijing.

Both Chinese President Xi Jinping and President Donald Trump have made clear that they are not afraid of a trade war that many fear could derail the global economy. On Tuesday, Xi's government announced retaliatory duties on $60 billion worth of American goods, a day after the U.S. slapped a 10 percent of tariffs on $200 billion of Chinese imports.

Chinese state media have warned that the country will "emerge stronger" from the situation.

Beijing officials "are convinced that the way they plan economic development in key sectors is the most successful way for them to become industry leaders, so they don't want to back away from that," Stratford explained.

"What the U.S. is asking the Chinese side to do is something the Chinese side clearly doesn't want to do, they don't think it's in their best interest," he continued. As a result, neither side may be ready to reach a compromise, he warned.