World steel demand will fall 15-20 percent this year, the steepest decline since World War Two, the head of ArcelorMittal said on Tuesday.

Lakshmi Mittal, chief executive of the world's largest steelmaker, told a shareholder meeting that Chinese demand was showing signs of improving and destocking in the United States was drawing to a close.

The company has halved production, but Mittal said that did not reflect demand. ArcelorMittal said demand should start to normalise once destocking is complete worldwide, provisionally at the end of the second quarter.

Mittal told shareholders that steelmakers had to ensure that, when the market did improve, production capacity was brought back at an appropriate speed so they do not make steel which cannot be sold.

The World Steel Association forecast late last month steel demand would tumble by 15 percent this year.

Mittal said two weeks ago, when the company published first-quarter results, that he was a little less pessimistic. (Reporting by Philip Blenkinsop; Editing by Dan Lalor)

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