The Bavarian sister party of Angela Merkel's Christian Democrats has given the German Chancellor two weeks to reach a European agreement on migrants before they would demand a crackdown that could collapse her fragile coalition.
The Christian Social Union (CSU) said they would delay a move to turn refugees away at the border if they had registered in other EU countries until after the EU summit at the end of the month.
The dispute between Ms Merkel and Horst Seehofer, the chairman of the Bavarian CSU, and also Germany's interior minister, has threatened to bring down the grand coalition between the two sister parties and the Social Democrats.
Mr Seehofer wants to start turning migrants away at the border if they have already registered in other EU member states.
Ms Merkel is opposed, saying she wants to reach agreement at EU level on how member states should handle the refugee situation.
Mr Seehofer has threatened to implement the crackdown, using his powers as interior minister.
That would be a direct threat to the Chancellor, meaning she would have to fire him, thus bringing about a collapse in the coalition.
Following intense talks over the weekend, the CSU has agreed to give Ms Merkel just under two weeks to see if she can reach a consensus at EU level.
At a news conference in Munich, the CSU chairman warned that if there was no agreement at EU level, then the crackdown would go ahead.
This afternoon, Ms Merkel said that any move to close Germany's borders would tie her hands in the negotiations.
Today's deal averts an immediate crisis, but the Social Democrats have said they would not automatically support it. The Chancellor's troubles are far from over.
Donald Trump blames migrants 'for German crime rise'
Earlier, US President Donald Trump blamed migrants in Europe for what he inaccurately described as a rise in crime in Germany and for violently changing the culture.
In a tweet he added that what was happening with immigration there presented similar threats to the United States.
"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!" he said.
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
Mr Trump's administration is facing strong criticism from rights activists, Democrats and some in his own Republican Party for separating children from their parents at the US-Mexican border, a policy aimed at deterring illegal immigration.
We don’t want what is happening with immigration in Europe to happen with us!— Donald J. Trump (@realDonaldTrump) June 18, 2018
Crime has fallen off dramatically in Germany, with the country's internal ministry reporting last month that criminal offences in Germany totaled 5.76 million in 2017, the lowest number since 1992, leading to the lowest crime rate for the country in more than 30 years.
Ms Merkel's open-door migrant policy is widely blamed for the rise of the right-wing AfD, now the main opposition party in Germany's federal parliament.
More than 1.6 million migrants, mostly Muslims fleeing wars in the Middle East, have arrived in Germany since 2014.
Additional reporting: Reuters