WASHINGTON, May 13 (Reuters) - U.S. Trade Representative Katherine Tai said on Thursday that she believes solutions to trade disputes with the European Union on aircraft subsidies and steel and aluminum tariffs "are within reach."

Tai told the U.S. House of Representatives Ways and Means Committee that she is "very serious" about resolving the 17-year Boeing-Airbus World Trade Organization dispute over subsidies within a four-month tariff truce due to expire this summer.

President Joe Biden's trade chief also told lawmakers that the administration needs to rethink Trade Promotion authority -- the "fast-track" negotiating authority for trade deals that expires on July 1 -- to make it more relevant to a U.S. economy that is recovering from the COVID-19 pandemic. (Reporting by David Lawder, Editing by Franklin Paul)