German Chancellor Angela Merkel has given a cautious response to the idea of a separate financial system to bypass US sanctions on Iran, possibly saving the 2015 nuclear deal.

Foreign Minister Heiko Maas suggested in the German newspaper Handelsblatt that Europe could set up its own payment system, getting around US restriction on the Iranian banking and finance sectors.

Merkel said on Wednesday, “It was an important contribution as it expresses in other words what I have said, that the transatlantic relationship is changing, we need to take more responsibility, Europe has to take its fate into its own hands.”

But she then hedged,”On the question of independent payment systems, we have some problems in our dealings with Iran, no question, on the other hand we know that on questions of terrorist financing, for example, SWIFT [the Belgian-based system for international transactions] is very important.”

The Chancellor offset the issue of the nuclear deal, threatened by US withdrawal and promise of comprehensive sanctions in November, by citing the importance of cooperation with the US on security.

Maas said in his column that it is essential for European autonomy to set up a European Monetary Fund and an independent SWIFT system.

But a Foreign Ministry spokeswoman pulled back from the specifics, framing Maas’s ideas as a debate on relations with Washington, rather than a plan. She said Germany is discussing possibilities with partners, including the UK and France, who are also in the 5+1 Powers who reached the nuclear agreement with Iran.

Since Trump’s withdrawal of the US from the deal in May, the European Union has said that it will try to protect its companies from US punishment over any links with Iran. But the EU has struggled to provide guarantees for large companies, with Washington implementing a first stage of new sanctions this month and promising stringent measures — including restrictions on Iran’s energy and financial sectors — from November 5.

As a result, some of Europe’s biggest companies have drawn down or suspended business with the Islamic Republic. Among them are Germany’s Siemens, Deutsche Telekom, and Deutsche Bahn.