The U.K.’s eventual Brexit deal could serve as a model for EU relations with Turkey and Ukraine, German Foreign Minister Sigmar Gabriel said in an interview published Tuesday.

Speaking to the Westdeutsche Allgemeine Zeitung, Gabriel said: “If we can get a smart deal with Britain that governs relations with Europe after Brexit, it could be a model for other countries: Ukraine and Turkey.”

With Turkey, the foreign minister proposed “a new, closer form of the customs union.”

Both Turkey and Ukraine want to be full members of the EU, but the bloc is hesitant to include the two. In Turkey, a crackdown on the police and the judiciary following a failed in coup in 2016 and the arrest of journalists and academics compelled European Commission President Jean-Claude Juncker to warn that “Turkey is moving away in giant strides” from Europe.

Ukraine is required to follow through with a host of judicial and economic reforms, including tackling corruption, before it can be a candidate. The Ukrainian government’s protracted conflict with Russian-backed separatists in the east also threatens the country’s stability.

If full membership isn’t an option, Gabriel said, “we have to think about alternative forms of closer cooperation.”