A customer looks at beef on display at a beef section in a discount store in Seoul, March 6. Yonhap

The U.S. nationwide cattlemen's group asked the Trump administration Tuesday to help lift Korea's import ban on American beef from cattle aged 30 months or older, noting that similar curbs have been lifted in China, Japan and Taiwan.

The National Cattlemen's Beef Association (NCBA) sent its comments to U.S. Trade Representative (USTR) Jamieson Greer as the USTR has requested those comments to "assist in reviewing and identifying unfair trade practices, and initiating all necessary actions to investigate harm from non-reciprocal arrangements."

The age restriction on U.S. beef was put in place in 2008 amid fears over mad cow disease, or bovine spongiform encephalopathy.

"The United States has some of the most rigorous standards and highest safeguards concerning bovine spongiform encephalopathy," the NCBA said. "And we should pursue consultations with Korea to discuss removing the age restriction and strengthening science-based trade between our countries."

It pointed to the growth in U.S. beef sales in Korea as evidence that consumer confidence has improved significantly since 2008.

"We recognize the 30-month age-based restriction on U.S. beef is a sensitive issue in Korea, but it is an issue that should not be ignored. Similar 30-month restrictions have been lifted in China, Japan and Taiwan because they recognize the safety and quality of U.S. beef," it said.

The Trump administration has been studying countries' trade practices and other issues as it plans to roll out country-by-country "reciprocal tariffs" on April 2, which are to be pegged to trading partners' duties, non-tariff barriers and exchange rate policies in pursuit of "reciprocity."

The USTR had received comments from various sectors since Feb. 20. (Yonhap)