German Chancellor Angela Merkel has warned that time is running out for a deal to keep Greece in the eurozone.

Speaking after the G7 summit in Germany, she said Europe would show solidarity but only if Greece "makes proposals and implements reforms".

Earlier, Greek Finance Minister Yanis Varoufakis said it was time to stop finger-pointing and find an agreement.

Other topics on the agenda at the G7 summit were climate change, countering extremism and the war in Ukraine.

It was held at the picturesque Schloss Elmau hotel in the Bavarian Alps and was attended by the leaders of the US, UK, Japan, France, Canada and Italy.

The summit is being held at the Schloss Elmau resort in the Bavarian Alps. Photo: AFP/BBC

Merkel, who hosted the event, said the Greek crisis had been a central part of discussions.

She reiterated her desire for Greece to remain part of the eurozone, but said: "There isn't much time left. Everyone is working intensively. Every day counts now."

The European Commission is asking for further reforms to Greece's economy, including tax increases and cuts in civil servants' salaries and pensions, before the next €7.2bn (£5.2bn) tranche of bailout money can be released.

Greece debt talks - main sticking points

-- International creditors want pension cuts, slimmer civil service, VAT reform, fewer tax rebates and more private sector investment, reports say

-- Tsipras has ruled out increased VAT on energy and reduced supplementary payments for poorer pensioners

-- Athens wants lower primary budget surplus targets, but both sides appear close to agreement. According to reports, creditors want a budget surplus of one percent of GDP this year and two percent next, while Greece has proposed 0.8 percent for 2015 and 1.5 percent for 2016

But Greece has robustly rejected these proposals without some form of debt restructuring agreement in return.

At the weekend, Varoufakis was quoted as saying the Commission's latest demands were "borderline insulting".

But speaking on a visit to the German capital Berlin on Monday, he told reporters: "It is time to stop pointing fingers at one another and it is time that we do our job... to come to an agreement."

Merkel is expected to meet with Greek Prime Minister Alexis Tsipras on the sidelines of a European Union-Latin America summit in Brussels on Wednesday.

Russia sanctions

The G7 also called for the decarbonisation of the global economy, pledging to move electricity generation towards renewable sources and nuclear by 2050.

However they stopped short of setting binding targets.

On Ukraine, Merkel said G7 countries hoped Russia would comply with a ceasefire agreement signed in February by pro-Moscow rebels and the Kiev government. But she added that sanctions could be strengthened if necessary.

US President Barack Obama echoed her comments, saying: "The G7 is making it clear that if necessary we stand ready to impose additional significant sanctions against Russia."

He added that Russian President Vladimir Putin must decide whether he still wants to wreck Russia's economy in pursuit of a "wrongheaded desire to recreate the glories of the Soviet empire".

Russia was excluded from the group of economic powers last year after Russia annexed Crimea.