German Chancellor Angela Merkel on Sunday defended her open-door policy for migrants, rejecting a limit on the number of refugees allowed into Germany, despite divisions within her government.Merkel said there was no Plan B for reducing the flow of migrants other than through cooperation with Turkey, efforts she said could unravel were Germany to cap the number of refugees it accepts."Sometimes I also face despair. Some things go too slowly. There are many conflicting interests in Europe," Merkel told the state broadcaster ARD. "But, it is my solemn duty to do everything I can so that Europe finds a collective way."Germany and Turkey have emerged as crucial players in the biggest migration crisis seen in Europe since World War II. At an EU-Turkey summit last November, the EU promised 3 billion euros ($3.28 billion) in aid to Turkey to support projects which would improve the living conditions of refugees in Turkey, and to address the problems caused by the influx of refugees. Germany saw an unprecedented 1.1 million asylum seekers arrive last year, many of them fleeing conflicts in Syria, Iraq and Afghanistan. Amidst growing domestic pressure, Chancellor Angela Merkel wants Turkey to help stem the flow of migrants coming to Europe. On Sunday, she spoke to Prime Minister Ahmet Davutoğlu to discuss the deal between the EU and Turkey.Merkel spelled out her intention to keep Germany's borders open without placing a limit on the number of refugees, a goal many in her own country and coalition government openly disagree with."There is so much violence and hardship on our doorstep," she said. "What is right for Germany in the long term? I think it is to keep Europe together and to show humanity."Merkel was once highly popular among Germans but has seen her ratings plummet because of her handling of the migrant issue. The majority of those surveyed by ARD earlier in February indicated that they are dissatisfied with her handling of the crisis. Merkel now faces what she described on Sunday as the biggest challenge since taking office one decade ago. She is struggling to secure a plan with other EU countries in dealing with the influx of migrants but is pinning her hopes on talks between EU leaders and Turkey on March 7 as well as a migration summit on March 18 and 19.After many failed attempts, the two impending meetings appear to be the final chance to reach an agreement on a joint response before warmer weather encourages more refugees to make the perilous journey across the Mediterranean. Despite this, Merkel said she would continue to fight for a European solution, even if the March 7 meeting were to fall short.The question of migrants has not only divided Europe but has also caused strong dissent within Germany and the governing coalition. Politicians from the state of Bavaria's Christian Social Union, the sister party to Merkel's CDU, have criticized Merkel's stance on the issue, asking that a quota be placed on the number of migrants allowed entry into the country. The majority of Germans polled in the ARD survey indicated that they share the sentiment of their Austrian counterparts, where a quota on refugees was recently imposed. Austria, the last stop on the way to Germany for hundreds of thousands of migrants, recently imposed restrictions on its borders, setting off a domino effect in Europe and limiting the flow of people, which has left hundreds stranded in Greece.Merkel dismissed such a "rigid limit" saying, "There is no point in believing that I can solve the problem through the unilateral closure of borders."GERMAN DIVIDEMerkel made her comments as the rift widened in her governing coalition over how to cope with the influx of refugees. Leading German Social Democrats, part of the country's governing coalition, have accused Merkel's conservative finance minister of being too stingy in dealing with the migrant crisis.The criticism came after Finance Minister Wolfgang Schaeuble labelled the Social Democrat proposals which would widen social spending on housing and public services to complement the integration of migrants as "pitiful."Stephan Weil, the Social Democrat premier of the state of Lower Saxony, fired back on Sunday, calling for a bigger social services budget as the country accommodates over a million migrants. Merkel said she did not support such an idea. "The finance minister obviously just doesn't get it," Weil told the Sueddeutsche Zeitung newspaper. Pointing to the high cost of integrating migrants into society, Weil said: "We cannot create the impression that this is happening at the expense of the weaker members of our society."Heiko Maas, a justice minister and Social Democrat, echoed the critical stance of his counterparts, making a renewed call for more spending. "What's more important? The people in the country or balancing the budget?"Schaeuble, a long-standing proponent of prudence, wants to prevent Germany from spending more than it earns and is unlikely to be easily moved.If spending were to spiral out of control, it could further weaken Merkel's fading support.While Merkel has warned of the consequences a border closure would have on Europe, a poor showing by the Christian Democrats in state elections in March could pressure her to reverse course."The international financial crisis was a big challenge. We managed that well. The euro crisis was a huge challenge," said Merkel. "This crisis is different because people are coming to us, people of a different cultural background ... where people ask, 'What is this doing to our country?'"Germany's chancellor said that she has seen nothing that would prompt her to change course. Commenting on her plan, Merkel, also a trained scientist, said, "It's all well thought through. It's logical."