The U.S. unilateral punishing trade measures, based on outdated national laws, against its trade partners are not in line with the international laws and could shaken the foundation of an established multilateral trade framework, a UN trade official warned on Tuesday.

U.S. President Donald Trump on Monday directed the U.S. trade representative (USTR) Robert Lighthizer to examine China's intellectual property practices, despite worries about potential harms to China-U.S. trade ties.

The USTR will determine "whether to investigate any of China's laws, policies, practices, or actions" that "may be harming American intellectual property rights, innovation or technology development" under Section 301 of the Trade Act of 1974, according to a memorandum released by the White House.

Section 301, once heavily used in the 1980s and the early 1990s, allows the U.S. president to unilaterally impose tariffs or other trade restrictions against foreign countries, but the U.S. has rarely used the trade tool since the WTO came into being in 1995.

Liang Guoyong, Economic Affairs Officer at the Investment and Enterprise Division of the UN Conference on Trade and Development (UNCTAD), said such an examination under Section 301 could serve as a tool for the U.S. to strike a bargain with China, and any tariffs or restricting trade measures thereof imposed unilaterally by the U.S. could shaken the foundation of a multilateral trade framework.

The repercussions would be a high risk of a trade war which will benefit neither of the two countries, he added.

Liang said that the multilateral trade framework centered on the WTO has provided not only enough room for specific countries to boost trade through legal and reasonable measures, but also a functional mechanism for countries to solve their trade disputes.

Resorting to unilateral punishing measures against trade partners based on national laws instead of rules within the WTO multilateral framework is not in line with the principles of justice and equality, and also against the international laws, he said.

China and the U.S. maintain one of the most important bilateral relations in the world, in which economic and trade relations are the cornerstone. A stable Sino-U.S. trade relation is crucial not only to their economic interest, but also to the revival of global trade and economy as a whole, Liang said.

He proposed that the two countries turn to constructive measures to address trade imbalance.

Resorting to extreme protectionist measures would yield nothing but loss, he said.