U.S. Trade Representative Robert Lighthizer will lead the next rounds of trade talks with China and he will push Beijing aggressively on making structural changes to its policies, White House trade policy adviser Peter Navarro told National Public Radio Monday.

"He’s the toughest negotiator we’ve ever [had] at the USTR and he’s going to go chapter and verse and get tariffs down, non-tariff barriers down and end all these structural practices that prevent market access," Navarro said.

The trade representative has been an unsparing critic of China's trade policies. Last week, just days before President Trump was sent to meet Chinese President Xi Jinping to discuss trade policy Lighthizer issued a statement slamming China's policies regarding automobiles and claiming that "all available tools" were being considered to respond.

On Saturday Trump agreed to hold off on ratcheting up tariffs on $200 billion of Chinese goods from 10 to 25 percent for 90 days in order to give the two sides time to reach a more permanent agreement.

Treasury Secretary Steven Mnuchin said Monday said that as part of that deal China offered "over $1.2 trillion in additional commitments" to buy U.S. goods. However, fundamental issues about China's trade policies still exist. "This isn't just about buying things. This is about opening markets to U.S. companies and protecting U.S. technology. Those are very important structural issues to the president," he told CNBC.

The Treasury secretary said that Trump himself would be the lead negotiator of the later talks. Spokesmen for the White House and U.S. Trade Representative's Office could not be reached for comment.

President Trump said Monday that Saturday's deal would benefit the domestic agricultural industry in particular. "Farmers will be a a very BIG and FAST beneficiary of our deal with China. They intend to start purchasing agricultural product immediately. We make the finest and cleanest product in the World, and that is what China wants. Farmers, I LOVE YOU!"