U.S. President Donald Trump is seen on a TV screen announcing tariffs on steel and aluminum, at the White House in Washington D.C., the United States, on March 8, 2018. (Xinhua/Ting Shen)

BRUSSELS, March 10 (Xinhua) -- There is no immediate clarity on the exact U.S procedure for the exemption from steel and aluminum tariffs, and discussions will continue next week, EU's Trade Commissioner Cecilia Malmstrom tweeted on Saturday after a trilateral meeting with her U.S. and Japanese counterparts in Brussels.

"As a close security and trade partner of the U.S., the EU must be excluded from the announced measures. No immediate clarity on the exact U.S. procedure for exemption however, so discussions will continue next week," she tweeted.

"EU, Japan, U.S. agreed on further steps in our ongoing cooperation to tackle trade--distorting practices in sectors such as steel. Stronger rules on industrial subsidies, etc.," she added.

The trilateral talks between Malmstrom and Japanese Minister for Economy, Trade and Industry Hiroshige Seko and U.S. Trade Representative Robert Lighthizer was followed by a bilateral meeting between Malmstrom and Lighthizer.

"I had a frank discussion with the U.S. side about the serious pending issue of steel and aluminium tariffs," she said.

The ministers agreed to meet again in the margins of the OECD ministerial meeting in Paris to discuss overcapacity issues.

U.S. President Donald Trump formally signed proclamations to impose 25 percent tariffs on steel imports and 10 percent on aluminum Thursday, with initial exemptions for Canada and Mexico, saying exemptions could be made for other countries through negotiations.

The EU has threatened to take retaliation measures if it is included in the those tariffs. The EU has prepared a list of products including orange juice, bourbon, cranberries, peanut butter etc., for imposing reciprocal tariffs if needed.

European Commission vice--president Jyrki Katainen said Friday that the EU is ready to take the U.S. to the World Trade Organization (WTO) court if some worst scenario happens.