WASHINGTON (Reuters) – The United States and China are on a good path to complete the first part of a trade agreement, but two additional phases will be needed to address all of China’s “structural deadly sins,” White House trade adviser Peter Navarro said on Friday.

Navarro told Fox Business Network the linchpin of the agreement was an enforcement mechanism that would allow the United States to impose tariffs for any violations of the agreement, without fear of retaliation by Beijing.

“We’re going to need three phases of the deal to deal with all the seven … structural deadly sins of China,” he said.

U.S. and Chinese officials on Friday said they had made good progress toward finalising a “phase one” trade agreement after nearly 16 months of tariffs that have slowed global growth.