GENEVA, March 22 (Xinhua) -- U.S. President Donald Trump's proposal to impose massive tariffs on imports from China could backfire and undercut the multilateral global trade system, trade experts warned Thursday.

Despite warnings from business groups and trade experts, Trump on Thursday signed a presidential memorandum that could impose tariffs of up to 60 billion U.S. dollars on imports from China, the latest unilateral move that poses a threat to global trade.

Trump has directed U.S. Trade Representative Robert Lighthizer to publish a list of proposed Chinese goods that could be subject to tariffs in 15 days.

The U.S. Treasury Department will have 60 days to propose restrictions on Chinese investment in the United States, according to the presidential memorandum.

The tariffs "could be about 60 billion" dollars, Trump said Thursday at the White House before signing the memorandum. But a senior White House official told reporters earlier in the day that the number would be close to 50 billion dollars.

Wallace Cheng, country director for China with Geneva-based think tank International Centre for Trade and Sustainable Development (ICTSD), said that the proposed high tariffs targeting Chinese imports are a case of Washington "shooting itself in the foot."

"China has plenty of countermeasures with which it could choose to retaliate, for example, cutting orders of Boeing, banning imports of beans and beef, etc," Cheng said.

Guoyong Liang, an economic officer at the United Nations Conference on Trade and Development (UNCTAD), said that he believes the way to resolve the trade imbalance between China and the United States should be expanding China's imports, rather than to limit China's exports to the United States.

"To this end, the two parties need to conduct effective negotiations and make necessary compromises," he said.

"Resorting to a trade war will lead to a loss on both sides, and have negative impacts on both economies as well as the global trade system," he added.

Noting that the existing multilateral system "provides effective trade remedy measures and dispute settlement mechanisms", he said that members of the World Trade Organization should resolve their disputes within the multilateral framework.

The proposed tariff against China came at the end of the USTR's eight-month probe of alleged intellectual property rights violations by China. The probe was launched under Section 301 of the 1974 Trade Act, which is widely seen as outdated.

Liang said that recourse to domestic laws and unilateral measures will threaten the authority and effectiveness of the multilateral trading system, and in the long run harms the stability and growth of the world economy.