Germany's Angela Merkel does not expect talks on Monday with Greek Prime Minister Alexis Tsipras to resolve his differences with the euro zone over Greece's bailout but she does want to hear from him in person about his reform plans, an aide said.

The German chancellor and Greek leader have played down expectations that he would use his first official visit to Berlin to present a brand new list of reform proposals which he promised European Union leaders at a summit last week.

Tsipras' talk of coming up with a new reform package within days to unlock the cash that Greece needs to avoid crashing out of the euro has met deep-seated scepticism in Germany, the currency zone's largest economy.

Merkel's spokesman Steffen Seibert said the meeting, which was scheduled for 5 p.m. local time (1600 GMT) followed by a joint news conference and then dinner, could not replace Greece's talks with all of its euro zone partners.

"Greece has an agreement with the Eurogroup, not a bilateral one with Germany. So if there is a reform list shortly as Greece has promised, it will be presented to the Eurogroup, not to individual governments," said Seibert.

But although the meeting was no "rival" to Eurogroup talks, "of course it's interesting for the chancellor to her from the Greek prime minister's mouth what his ideas are", Seibert said.

News that Tsipras wrote to Merkel last week warning that it would be impossible for Greece to make debt payments in the next few weeks without more financial help provided an unpromising backdrop for talk that already promised to be tense.

"It's not a threat, it's reality," a spokesman for the Greek government, Gabriel Sakellaridis, told Mega TV when asked if the March 15 letter was meant to make it clear Athens would choose paying wages over replaying its debt.

"It was a letter which said more or less what we have been saying since last week - that there is a liquidity problem and that what at is needed is political initiatives," he said.

Tsipras blamed European Central Bank limits on Greece's ability to issue short-term debt as well as euro zone bailout authorities' refusal to disburse any cash before Athens adopts new reforms, according to the Financial Times newspaper.

Mistrust and scepticism among Merkel's allies have spawned portrayals of the talks as a Wild West-style showdown, with the German media casting Tsipras as the outlaw and the chancellor as a sheriff fighting to keep the euro zone together.

Although Merkel acknowledged last week that she and Tsipras would talk "and perhaps also argue", she said it would not be a defining moment in the standoff over the terms of Greece's 240 billion euro ($260 billion) bailout.

The mistrust felt by Merkel's conservatives towards Tsipras' leftist government - and especially his Finance Minister Yanis Varoufakis - was unlikely to be improved by Tsipras' plans to meet leaders of Germany's radical Left party on Tuesday.

Berlin also pre-empted any Greek attempt to link the bailout debate to Athens' revival of reparation claims from the Nazi occupation of Greece in World War Two. This issue "is a closed chapter for us", said a German foreign ministry spokesman.