WEST MIFFLIN, Pennsylvania, May 30 (Reuters) - U.S. President Donald Trump said on Friday he planned to increase tariffs on imported steel and aluminum to 50% from 25%, ratcheting up pressure on global steel producers and deepening his trade war.

"We are going to be imposing a 25% increase. We're going to bring it from 25% to 50% - the tariffs on steel into the United States of America, which will even further secure the steel industry in the United States," he said at a rally in Pennsylvania.