Japan told the World Trade Organization on Friday it was ready to take retaliatory measures against US tariffs on its steel and aluminium, reversing its earlier conciliatory stance toward its close ally.
Japan informed the WTO it had the right to impose tariffs on US goods worth 50 billion yen ($451 million) -- equivalent to the impact of the US tariffs newly imposed on Japanese metal products, the foreign ministry said in a statement.
But the ministry stopped short of saying when Tokyo might take action, saying: "We plan to decide appropriately, considering the impact on Japanese companies as well as related US measures."
US President Donald Trump sparked fears of a trade war in March when he decided to impose 25 percent tariffs on steel and 10 percent on aluminium imports, primarily to target China, but also allies, including EU countries as well as Japan.
Marking a departure from a decades-long US-led drive for open and free trade, Trump has claimed that massive flows of imports to the US threatened national security.
While Washington has granted Europe and other allies a delay from imposing the controversial levies, Japan remains on the list of countries facing the tariffs.
China has already taken retaliatory measures but Japan had taken a conciliatory approach, attempting to win exemptions through dialogue.
The trade row has cast clouds over the relationship between Prime Minister Shinzo Abe and Trump, who have forged otherwise close ties pledging together to rid North Korea of nuclear weapons.
Ahead of a summit with Abe in April, Trump tweeted that Japan "has hit us hard on trade for years".
Japan has warned the tariffs "could have a grave impact on the economic relationship" between the world's first and third-largest economies.
Japan's top government spokesman Yoshihide Suga said in March the move could harm the global trading system and the entire world economy and said Tokyo would urge the US to grant the country an exemption.
The tariff dispute is expected to be high on the agenda when Japanese Economy Minister Toshimitsu Motegi and US Trade Representative Robert Lighthizer hold talks as early as mid-June.
Japan's politically sensitive trade surplus with the US rose three percent last year, while its overall surplus with the world dropped more than 27 percent.
Exports of steel and aluminium products to the US came to some 200 billion yen last year.
For decades into the 1990s, the two countries battled over their trade flows, but the balance has become less of a hot-button issue under recent US administrations, with China's trade surplus a greater concern for Washington.
© 2018 AFP