WASHINGTON — U.S. President Donald Trump's administration on Thursday announced its final decision to impose up to 12.5 percent tariffs on South Korea, Japan and other trading partners over forced labor concerns.

The Office of the U.S. Trade Representative (USTR) unveiled the new tariffs ranging from 10 percent to 12.5 percent on dozens of countries after conducting investigations into 60 economies under Section 301 of the 1974 Trade Act to determine whether they had taken sufficient steps to ban imports made with forced labor.

The announcement came as the administration's temporary 10-percent global tariffs were set to expire on Friday. The across-the-board duties were rolled out after the Supreme Court struck down the Trump administration's country-specific "reciprocal tariffs" in February.

Last month, the USTR proposed a 12.5 percent tariff on Korea and other economies over forced labor concerns.

In comments submitted to the USTR, the Korean government had urged the U.S. to reconsider the proposed forced labor tariff, calling the proposal "unwarranted" and "disproportionate" given the relevant circumstances of Asia's fourth-largest economy.

Separate from the investigations on forced labor concerns, the USTR office has also conducted Section 301 investigations into Korea, China, Japan and 13 other trading partners to uncover "unfair" trade practices related to "structural" excess capacity and production.

The investigations came as the Trump administration sought to replace the invalidated reciprocal tariffs that it had imposed under the 1977 International Emergency Economic Powers Act.