German Chancellor Angela Merkel arrives in Greece on Tuesday to support its embattled government amid planned new anti-austerity protests, her first visit since the economic crisis erupted more than two years ago. Thousands of police will create a safety zone for Merkel\'s meetings with conservative Prime Minister Antonis Samaras and President Carolos Papoulias, aiming to keep demonstrators at arm\'s length. Some 6,500 officers backed by water cannon and a helicopter have been mobilised for the German chancellor\'s six-hour visit, the first since the economic crisis made landfall in Greece in 2010. Merkel had faced criticism in Germany for failing to visit Athens thus far during the crisis, unlike EU President Herman Van Rompuy, European Commission president Jose Manuel Barroso and eurozone chief Jean-Claude Juncker. In August, when Samaras visited Berlin, Merkel had insisted that she wanted the debt-wracked country to stay in the euro and pledged German help after crisis talks with the Greek prime minister. Merkel\'s office on Monday said she would convey a message of support for \"ambitious\" cuts already in place in Athens and encouragement to stay the course. \"She is going to Greece to express her support for the ambitious reform efforts that the Greeks have set out and are -- in part -- beginning to implement,\" Steffen Seibert told a news conference. \"We should not forget -- and I think this is sometimes forgotten in Germany -- that Greece can point to some successes when it comes to reducing the deficit through very difficult measures,\" added the spokesman. Samaras will greet Merkel at Athens airport at 1030 GMT and the two will hold talks at 1115 GMT, after which they will address the press. Merkel is then scheduled to see President Papoulias at 1345 GMT. \"We believe this is a message of faith in the course of the Greek government, the Greek economy,\" government spokesman Simos Kedikoglou told Antenna television. \"It is a positive step, it\'s important that the German chancellor is coming to Greece for the first time since the start of the crisis,\" he said. Leftist and Communist-affiliated unions are holding separate protests at 1000 GMT and a three-hour strike has been called in Athens from midday onwards. The police declared a ban on \"public gatherings and demonstrations\" in a broad section of the city centre that includes the German embassy, parliament and the offices of government but the union gatherings lie outside this area and will be held as planned. Merkel\'s route from the airport is also off-bounds. \"Syndicates and all of society will give a dynamic response to the plans of Merkel and European powers that are imposed by creditors and implemented by the government,\" the main Greek unions said in a statement. The German leader is a popular hate figure in Greece, often blamed for harsh austerity measures imposed by the government in return for vital international aid, and has in the past been depicted as Adolf Hitler in tabloid caricatures. Last month, during a general strike against spending cuts, protesters marching past the Bank of Greece crossed out \"Greece\" on the bank\'s sign and wrote \"Merkel\" over it. Samaras has assured Merkel that she will be \"welcomed in the appropriate way for the leader of a major power and a friendly country\", but many in Greece object to the visit. \"(Merkel) is coming to rescue a corrupt and discredited political system that is subject to her interests,\" said Alexis Tsipras, leader of radical leftwing opposition party Syriza that is taking a leading role in the protests. Leader of popular nationalist party Independent Greeks, Panos Kammenos, has also called for a gathering outside the German embassy. The visit comes at a crucial time for the heavily indebted country, which is in the midst of negotiations with its international creditors over a 13.5-billion-euro ($17.5 billion) package of cuts. A positive outcome is vital to unblock a 31.5-billion-euro installment from Greece\'s EU-IMF bailout package, which is needed to recapitalise banks and repay outstanding domestic debts in a country that is heading for a sixth straight year of recession.