PRESIDENT-elect Donald Trump believes Angela Merkel made “one very catastrophic mistake” with her open-door refugee policy, which has allowed a wave of more than one million migrants into Germany. He claimed his relationship with Merkel “may not last long at all” as he slammed the German chancellor for allowing the migrant crisis to get out of control. Mr Trump also hit out at the EU, abelling the crumbling Brussels bloc “a vehicle for Germany” and he suggested more countries will follow Britain’s “smart” decision in voting to leave.He added: “If refugees keep pouring into different parts of Europe… it’s going to be very hard to keep it together because people are angry about it.” Mr Trump’s glowing praise for Brexit came as he slammed the EU, suggesting it functions primarily to serve Germany’s interests and ranking Merkel alongside Russian president Vladimir Putin in international leaders he fears could be problematic. He said: “You look at the European Union and it’s Germany.“Basically a vehicle for Germany. “That’s why I thought the UK was so smart in getting out.” Mr Trump added: "I think she made one very catastrophic mistake and that was taking all of these illegals.""I do believe this, if they (EU countries) hadn't been forced to take in all of the refugees, so many, with all the problems that it entails, I think that you wouldn't have a Brexit. "It probably could have worked out but this was the final straw, this was the final straw that broke the camel's back." In another huge blow to Brussels, the President-elect promised to work quickly to secure a trade deal with the UK as it prepares to leave the stagnating union.Just days before he takes over the presidency, Mr Trump told Mr Gove: "Brexit is going to end up being a great thing. "We're gonna work very hard to get it done quickly and done properly. Good for both sides." The news comes as Washington’s EU ambassador Anthony Gardner confirmed Mr Trump’s team has been calling EU leaders to find out “which country is going to leave next”.