European Union leaders hoped early Tuesday they reached the outlines for a possible deal with Ankara to return thousands of refugees to Turkey and said they were confident a full agreement could be reached at a summit next week.

After months of disagreements and increasing bickering among the 28 EU nations, French President François Hollande said that "the summit has created hope that the refugee question can be dealt with through solidarity in Europe, and efficiency in cooperation with Turkey."

All eyes centered now on March 17 and the start of a two-day summit to finalize the commitment and clinch an iron-clad deal which the leaders hope would allow for a return to normalcy at their borders by the end of the year.

Turkey said it would be willing to make greater efforts to contain irregular migration. "The truth is that Turkey came to the summit with attractive proposals," said Greek Prime Minister Alex Tsipras.

EU President Donald Tusk said that after a week of shuttle diplomacy in and around Turkey, "we have a breakthrough now."

During 12 hours of negotiations, Turkey insisted that any agreement would require Europe to advance Turkey's accession to the bloc. Turkey also said it expects EU nations to ease its visa restrictions on Turkish citizens within months.

The EU has so far pledged a funding of 3 billion euros ($3.3 billion) to Turkey that is home to 2.75 million refugees chiefly from neighboring Syria. "Turkey is ready to work with the EU, and Turkey is ready to be a member of the EU as well," Turkish Prime Minister Ahmet Davutoğlu told reporters in Brussels.

Davutoğlu also added that the funds would only go to Syrian refugees. "Not one euro will go to Turkish citizens. Every penny will be spent for Syrian refugees."

British Prime Minister David Cameron said that "we do have the basis for a breakthrough which is the possibility that in future all refugees who arrive in Greece will be returned to Turkey." The sides will now reconvene at a two-day summit starting March 17.

For its part, the EU sought to gain stronger commitments from Turkey to take back refugees who have reached European shores and ease a crisis that has left an estimated 13,000 to 14,000 souls encamped in the wintry cold on the Greece-Macedonia border.

"To stop refugees arriving in Greece, we have to cooperate with Turkey," French President François Hollande said. Even though many saw the outlines of a deal, it was still too early to clinch it.

In capital Ankara President Recep Tayyip Erdoğan said that the EU failed to provide enough of the already pledged funds. He also criticized Europe for refusing to accept asylum seekers more readily, linking that policy to needless deaths as thousands opt to cross illegally by sea from the Turkish coast to offshore Greek islands.

"We are not sending them. They are going by sea and many of them are dying. We have rescued close to 100,000 from the sea," Erdoğan said in a speech.

Turkey is seeking a new EU commitment to take Syrians and other high-percentage refugee applicants via safe travel routes, such as at the land border between Turkey and Greece, to reduce drowning deaths in the Aegean Sea.

Of immediate concern was the plight of people stuck at Greece's northern border with non-EU member Macedonia, which for the past year has been one of the most popular routes for asylum seekers to reach central Europe via the Balkans. Hundreds of thousands of people have used the route in recent months to try to reach Germany, Sweden and other preferred destinations.

Macedonia now has effectively sealed off that route, a position backed by Austria, Croatia, Serbia, Slovenia and Hungary. Cash-strapped Greece has struggled to cope with the rapid buildup of humanity.

Those camped on the border vowed Monday to press on into Europe, regardless of what diplomats decide in Brussels.

"Whatever it takes, we will go. We have nothing to go back to. Our homes are destroyed," said Lasgeen Hassan, a Syrian who hopes to reunite with relatives already in Germany.