Washington, March 1 (CNA) The United States Trade Representative (USTR) has expressed "serious concerns" about Taiwan's agricultural polices that "are not based on science" and cited removing barriers to U.S. pork and beef products as high on its agenda.

"Priorities for the United States included removing Taiwan's various barriers to market access for U.S. pork and beef products," the USTR said in its 2021 Trade Policy Agenda and 2020 Annual Report, released Monday.

The report also highlighted "Taiwan's rice procurement systems, the regulatory process for setting pesticide maximum residue limits, and market access barriers facing U.S. agricultural biotechnology products" as other priorities for the trade office.

There was no acknowledgement in the report that Taiwan took a step toward addressing the concerns on the pork and beef issues late last year.

It controversially lifted a ban on ractopamine, a leanness-enhancing feed additive, in imported pork starting on Jan. 1, replacing it with maximum residue level (MRL) standards based on those set by the Codex Alimentarius Commission.

Taiwan also removed a ban on U.S. beef from cattle aged over 30 months.

President Tsai Ing-wen (蔡英文), who described beef with ractopamine as "toxic" when her Democratic Progressive Party was an opposition party, announced the moves on Aug. 28, 2020.

They were widely viewed as an effort by the government to satisfy U.S. prerequisites for any negotiations on a bilateral trade deal, but have been criticized as sacrificing the health of Taiwan's people and the country's food safety standards.

A poll conducted by the Taiwan Public Opinion Foundation in late January found that 66.3 percent of respondents were not satisfied or very dissatisfied with the move on opening Taiwan to pork containing ractopamine, compared to 28.2 percent who backed it.

Though the decision to remove the restrictions was well-received by members of both parties in the U.S. Congress, then-President Donald Trump's top trade negotiator, Robert Lighthizer, never publicly acknowledged the move.

President Joe Biden has said he will focus on resolving domestic issues before entering into any new trade agreements.

The report outlined other areas discussed in 2020, saying that the USTR and Taiwan engaged each other on intellectual property issues and issues related to transparency and predictability in pharmaceutical and medical device pricing and reimbursement.

The U.S. also went through working groups under the Trade and Investment Framework Agreement (TIFA) to address priority investment issues and improve Taiwan's investment climate and ensure that technical regulations do not create excessive burdens for the industries they affect, the report said.