LONDON- Europe's steel lobby expects the European Union and the United States to resolve a dispute within days over tariffs imposed in 2018 by Donald Trump.

The former U.S. President hit the EU, along with others such as China, India, Russia and Switzerland, with tariffs of 25% on steel and 10% on aluminium.

"I think it (a deal) is quite likely ...t here is much more at stake than steel and steel tariffs," Karl Tachelet of the European Steel Association or EUROFER told a webinar.

Tachelet said EU steel exports to the United States had slumped by 1 million tonnes to around 2.3 million since the 232 tariffs were imposed.

The two sides are seeking to replace them with an arrangement to allow duty-free entry of a specified quota of EU steel, Tachelet said. The U.S. trade representative was optimistic last week about a deal.

If a deal is not agreed, then retaliatory measures imposed by the EU are set to double on Dec. 1, said Tachelet, director of international relations and external affairs of the group.

"The EU needs to prepare and publish a decision to stop the train, but that will take some weeks... so we need to know by the first of November whether we have a deal or not."

The U.S. is under pressure from its steel sector not to make changes because the tariffs have been "a real industrial policy success" with higher output and new capacity, Tachelet added.

A European Commission source told Reuters that member countries were losing patience and that a successful outcome largely hinged on U.S. political considerations.

"If we get an agreement depends on whether the U.S. administration is ready to stand up to interests in swing states such as Pennsylvania," the source said this week.

(Additional reporting by Philip Blenkinsop in Brussels; Editing by Alexander Smith) ((eric.onstad@thomsonreuters.com; +44 20 7542 7093; Twitter https://twitter.com/reutersEricO; Reuters Messaging: eric.onstad.thomsonreuters.com@reuters.net))