Germans are rejecting their Chancellor’s open-door mass-migration policy, which has “violently changed their culture”, U.S. President Donald J. Trump has said in an attack on Angela Merkel.

The leader of the Christian Democratic Union (CDU) is currently fighting for her political life after she refused to consider migration reforms, including returning illegals to the border if they have been rejected for asylum in other nations.

The changes are being pushed by the CDU’s Bavarian allies, the Christian Social Union (CSU), led by interior minister Horst Seehofer, a long-standing critic of Mrs Merkel and her support for mass immigration.

On Monday, she was given a two-week ultimatum by the CSU and Mr Seehofer, who said they would start rejecting asylum seekers at the Bavarian border unless she sets tougher migration controls at an EU level.

President Trump blasted on Twitter: “The people of Germany are turning against their leadership as migration is rocking the already tenuous Berlin coalition. Crime in Germany is way up.

He added: “Big mistake made all over Europe in allowing millions of people in who have so strongly and violently changed their culture!”

The people of Germany are turning against their leadership as migration is rocking the already tenuous Berlin coalition. Crime in Germany is way up. Big mistake made all over Europe in allowing millions of people in who have so strongly and violently changed their culture! — Donald J. Trump (@realDonaldTrump) June 18, 2018

In September last year, Mrs Merkel narrowly secured a fourth term as Chancellor, as her party suffered their worst electoral performance since the war and the populist, anti-mass migration Alternative for Germany (AfD) secured 13 percent of the vote and entered the legislature for the first time.

The vote was widely seen as a rejection of the status quo on open borders and migration, and many expected Mrs Merkel to respond.

“We don’t want what is happening with immigration in Europe to happen with us!” President Trump also tweeted on Monday.

Germany has been shocked by a number of scandals linked to migrants since the peak of the crisis in 2015.

This includes the mass, coordinated, sexual assault of women on New Year’s Eve, mainly committed by asylum seekers, and a series of terror attacks conducted by migrants and Islamist extremists. A government study has also linked the massive influx of migrants in 2015 to rising levels of violent crime in Germany.

In contrast to Germany, Mr Trump is currently pursuing a “zero tolerance” approach to illegal migrants crossing the U.S. southern border, which has included separating children from the parents.