SEOUL—The U.S. and South Korea agreed to amend their free-trade deal to address American concerns about a growing deficit and resolve friction over tariffs on South Korean steel, Seoul’s trade ministry said in a statement Monday.

The changes to the deal, which have been blamed by President Donald Trump for expanding the U.S. trade deficit, focus on rebalancing trade in the auto sector—a major source of South Korea’s trade surplus with the U.S., the ministry statement said.

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