Germany's finance minister visited Greece on Thursday amid massive police security, insisting there was "no convenient shortcut" for the country's debt problems despite an alarming increase in poverty and unemployment during the crisis.

The 70-year-old Wolfgang Schaeuble is widely seen in Greece as an enforcer of the country's harsh austerity measures and has been often singled out for criticism by protesters.

Security concerns over his one-day visit, which occurred a day after Parliament narrowly agreed to thousands of public-sector job cuts, were such that 4,000 police were deployed and demonstrations were banned throughout central Athens.

Schaeuble, on his first visit to Greece since its financial crisis broke out in 2009, said the country had taken "big steps" to try and balance its budget. But he added that the debt-strapped country had little choice other than to press ahead with painful reforms.

"There is no way around structural and fiscal reforms that are currently being carried out. The only way to achieve sustainable growth is to make the economy competitive and reduce public deficits," Schaeuble said, speaking in English.

"There is no convenient shortcut. We Germans know this. Ten years ago we were the sick man of Europe. We had to take a long and painful path to become the very center of growth and anchor of stability in Europe."

Schaeuble discouraged talk of Greece receiving a second write-off, or "haircut," on its public debt following the massive debt restructuring deal agreed to with private sector bondholders last year. Most of Greece's debt is now owed to other eurozone governments in the form of bailout loans.

"I would like to ask all of you not to continue with this discussion about a new haircut, as it's not in your interest," he said. He argued that writing off some of the bailout loans Greece owes would undermine confidence in Europe's rescue programs by proving they are not reliable.

"You will destroy any confidence. If you take guarantees and then you are discussing a haircut, then you are a liar. And I'm not a liar."

Demonstrations have been banned throughout Athens during Schaeuble's trip. The German minister met conservative Prime Minister Antonis Samaras and other senior Greek officials, and was due later Thursday to sign a cooperation agreement between Greece and the government-owned German bank KfW.

Police placed parliament and the city's main Syntagma Square off limits to protesters, in security measures that were more extensive than those reserved for heads of government. Busy downtown subway stations were also closed for the day, while traffic restrictions were imposed along the route from Athens International Airport into the capital.

Tough austerity measures have helped keep Greece in the euro but unemployment has surged to 27 percent since the country was first bailed out in 2010 by other euro countries and the International Monetary Fund.

Left-wing opposition leader Alexis Tsipras accused Samaras of trying to help his fellow conservatives in Germany ahead of the federal election there in September.

"Mr. Samaras is acting like a manager for the (German) Christian Democrat party, as Mr. Schaeuble tours the countryside," Tsipras said in parliament Wednesday.

"He is coming here to support his catastrophic policies."

Parliament late Wednesday narrowly approved new austerity measures demanded by rescue creditors which will mean mass firings and transfers of workers in Greece's bloated public sector, a measure that has triggered a new round of large protests.

Greece's two largest unions are not planning demonstrations Thursday but striking municipal workers are expected to hold an afternoon rally.

Tsipras' left-wing Syriza party described the police measures as "fascist and undemocratic" and said its members would join demonstrations if they take place.