WASHINGTON – U.S. presidential candidate Hillary Clinton warned Tuesday she would take retaliatory action against Japan and China if she wins the White House, saying the two nations have intentionally weakened their currencies to aid exporters.

“China, Japan and other Asian economies kept their goods artificially cheap for years by holding down the value of their currencies,” Clinton said in a column published in the daily Portland Press Herald in Maine.

The former secretary of state is in the lead to win the presidential nomination of President Barack Obama’s Democratic Party for the Nov. 8 election, U.S. media polls and primary election results show.

“We need to crack down on currency manipulation — which can be destructive for American workers,” Clinton said, claiming foreign exchange problems have hurt the U.S. labor market.

“We need to expand our toolbox to include effective new remedies” such as retaliatory duties or tariffs on imported goods, she said.

Clinton reiterated her opposition to the Trans-Pacific Partnership, the giant free trade agreement the Obama administration signed with Japan and 10 other Pacific Rim countries as part of steps to revitalize the U.S. economy.

She expressed opposition to a trade deal that she said would fail to create jobs or raise wages for American workers, and also said she “would oppose future agreements if they failed to meet that bar.”

China is not a member of the TPP, which will cover some 40 percent of the global economy if ratified by all member nations.