ATHENS/AMSTERDAM, Aug 11 (Reuters) - The European Union is no position to deal with a repeat of the 2015 migration crisis and must try to keep people from fleeing conflict in Afghanistan, Greece said on Wednesday, as unity between EU member states over deportations crumbled. Greece, which last week co-signed a letter with five other EU countries saying deportations of failed asylum-seekers should continue despite the fighting, said ending such returns "would send the wrong message". "It would lead to more people trying to leave and come to the European Union," Migration Minister Notis Mitarachi told Reuters. However, two other signatories to the letter, the Netherlands and Germany, abruptly reversed course on Wednesday, saying they would not, for now, deport Afghan citizens who are seeking asylum, given the rapidly escalating conflict there. Among other signatories, Austria said it was sticking to its position and Denmark and Belgium declined to comment. But German Interior Minister Horst Seehofer said a state based on the rule of law had a responsibility to ensure any deportations did not put people in danger. "The security situation is changing so rapidly that we cannot meet this responsibility," he said. DIFFERENCES The disagreement underlined the differences over the issue within the EU, which Mitarachi said was unprepared for a repeat of the 2015 migrant crisis when more than a million people, most of them Syrians, Afghans and Iraqis, arrived seeking refuge. "Absolutely not, the EU is not ready and does not have the capacity to handle another major migration crisis," he said. For now, the issue is largely theoretical as returns have not been possible due to the Afghan situation. Last week Germany cancelled a flight due to deport six Afghans convicted of criminal offences to Kabul because of security risks. Fears of a new migrant crisis have escalated as Taliban fighters have made sudden, strong gains in their campaign to defeat the Kabul government following the withdrawal of U.S.-led foreign forces after a 20-year presence. read more Mitarachi said the EU should offer more support to help Greece"s neighbour Turkey handle more arrivals from Afghanistan. A European Commission spokesperson said on Tuesday it was for member states to determine their approach to deportations. However, a senior EU official said it was "hard to imagine" forced returns would go ahead in current conditions. read more