This file photo, released by AFP, shows a metal product factory in Ohio. (PHOTO NOT FOR SALE) (Yonhap)

WASHINGTON -- Three senators from Rust Belt states have called on the US government to reduce the import quota for South Korean metal products used in the production of oil and gas, saying the reduced demand and high levels of Korean imports are affecting American companies and workers.

Senators Sherrod Brown (D-OH), Bob Casey (D-PA), and John Fetterman (D-PA) wrote a letter to Commerce Secretary Gina Raimondo and US Trade Representative Katherine Tai on Thursday, taking issue with the quota for South Korean oil country tubular goods (OCTG). OCTG refers to rolled metal products, such as drill pipes and structural pipes.

"This quota was originally established in 2018 but is now outdated and ineffective due to lower demand for OCTG," they said in the letter, referring to the South Korean imports.

"We respectfully encourage you to reduce this quota to reflect the lower demand and to level the playing field for the domestic OCTG industry," they added.

In 2018, the US announced tariffs at rates of 25 percent and 10 percent on certain steel and aluminum imports, including OCTG, covering most US trading partners, but with certain exemptions for US allies like South Korea.

An annual quota of 508,020 short tons was implemented for South Korean OCTG imports. This quota has remained constant since its inception, except for a 40 percent quota reduction for one year in 2020 in response to a significant decrease in demand due to the COVID-19 pandemic, according to the senators.

"The reduced demand coupled with high levels of South Korean imports is hurting American OCTG companies and has resulted in over 220 layoffs and/or reductions in workforce at plants in Ohio, Pennsylvania, Oklahoma, and Texas," they said in the letter.

"This is unacceptable. We know American workers are the best in the world and can compete with anyone if they have a level playing field. We urge the administration to take action to ensure that the industry does not continue to suffer additional job losses because of this outdated quota."

They also pointed out the importance of the domestic OCTG industry in securing America's "energy independence."