US Trade Representative Katherine Tai (second from R) and South Korean Trade Minister Yeo Han-koo (third from R) pose for a photo during their joint visit to SK Siltron CSS, a semiconductor manufacturer under South Korea's SK Group, in Bay City, Michigan on Wednesday. (Yonhap)

BAY CITY, Michigan -- The South Korea-US free trade agreement (KORUS FTA) has greatly increased bilateral trade and investment but more can and should be done to further advance the countries' economic ties, US Trade Representative Katherine Tai said Wednesday.

Her remarks come as the allies marked the 10th anniversary of the implementation of their bilateral trade pact this week.

"In the 10 years since KORUS (FTA) was signed and took effect, the trade relationship between the United States and Korea has really flourished," Tai said.

"Today, Korea is our sixth largest trading partner and over the last decade, when we look at the data, the value of our goods and services exports to Korea has grown by over 17 percent to nearly $70 billion," she added.

Seoul earlier said trade between the two countries has jumped nearly 70 percent in the 10 years since the KORUS FTA was implemented on March 16, 2012, adding bilateral investment has also more than doubled in both directions.

Tai noted Michigan alone enjoyed a 420-percent increase in its exports of "made in America" vehicles to South Korea over the past decade, with its overall shipments to South Korea soaring over 30 percent over the cited period.

"And while this is notable progress, we have much further to go and we will continue to focus on expanding opportunities for US autos exports to Korea beyond just increased exports," she said on her trip to the factory of SK Siltron CSS in Michigan, a semiconductor manufacturer under South Korea's SK Group.

The USTR was joined by South Korean Trade Minister Yeo Han-koo on her visit to Bay City, a city of some 31,000 people, and Auburn with an estimated population of less than 2,100.

"However, we also know that trade and trade agreements alone are not enough to maintain our competitive edge in the global economy," she added, calling for increased investment at home.

Tai welcomed SK Group's plan to invest $300 million over the next years to build its second production facility in Bay City, which, she said, is expected to double the company's employment in Michigan and also increase the countries' "collective semiconductor production capacity."

"This partnership between our two countries is an excellent example of how we can harness the innovation and talent of our citizens to create a cleaner, more sustainable economy while also creating good paying jobs along the way," she said.