European Union leaders hailed a "breakthrough" with Turkey on a proposal on Monday to curb the migrant crisis, but are delaying a decision until a summit next week to consider Ankara's new demands.
Turkish Prime Minister Ahmet Davutoglu said his country would take back the large numbers of economic migrants that illegally cross from Turkey to Greek islands.
"Many agreed that this was a breakthrough," said Merkel.
Davutoglu surprised many EU leaders with the plans, which also included a call for more legal immigration from Turkey to the EU as well as doubling EU aid to refugees in Turkey by adding another €3 billion.
The summit on the refugee crisis powered on for 12 hours and the conversation will continue on March 17th and 18th to work out a definitive agreement.
More than one million refugees and migrants have arrived in Europe since the start of 2015 - mostly arriving in Greece from Turkey - with nearly 4,000 dying while crossing the Mediterranean.
Still, a final statement from the summit read: "Irregular flows of migrants along the Western Balkans route have now come to an end".
Davutoglu also wanted to discuss Turkey's potential for joining the EU, but Merkel said that "the question of joining is not on the table right now".