ROME (Reuters) - Italy's industry minister pledged on Tuesday to support business deals with Iran potentially worth billions of dollars, undeterred by fears U.S. President-elect Donald Trump could put slowly thawing international relations back on ice.

Iran re-joined the global trading system in January after a multilateral deal between world powers, and Italian firms eagerly started drawing up commercial agreements.

Trump has raised the prospect the United States could pull out of the pact, which lifted many sanctions in exchange for limiting the Islamic Republic's nuclear ambitions, leaving European diplomats fearing the change of leadership at the White House could thwart growing trade.

But Italian Industry Minister Carlo Calenda said he would continue to work to strengthen trade ties, and travel to Iran in early 2017 along with Economy Minister Pier Carlo Padoan.

The issue of funding investment, which Tehran complains has been held up by continued U.S. sanctions restricting Iran's access to the international banking and financial system, would be high on the agenda, he said.

"The central issue is to make financing channels work fully, so that all the good projects we have can become reality," Calenda said at a trade fair in Rome for Iranian companies.

Calenda said it was too early to say how the picture could change under Trump's leadership, but in the interests of the countries involved "I think there is the absolute necessity to implement the (nuclear) agreement and move forward that way".

Asked whether any of the collaboration agreements made so far, which have involved oil services group Saipem <SPMI.MI> and steel firm Danieli <DANI.MI>, were at risk, Calenda said: "No, I don't think so."

Iran denies that its nuclear program has military aims.

(Reporting by Isla Binnie; Editing by Alison Williams)