Eurozone finance ministers told Greece on Monday to speed up work aimed at reaching an agreement with its creditors on the country's reform plans, amid fears that Athens could soon run out of money, according to dpa. Greece has been trying to access 7.2 billion euros (8.15 billion dollars) in remaining bailout funds, but its creditors - the European Commission, the European Central Bank and the International Monetary Fund (IMF) - have refused to transfer the money until Athens agrees to new reforms. The Eurogroup of eurozone finance ministers welcomed recent progress, but warned in a joint statement that "more time and effort are needed to bridge the gaps on the remaining open issues." An agreement must be reached within the next two to three weeks in order to meet a June 30 deadline, an EU diplomat said on condition of anonymity. The extra time is necessary to seek parliamentary approval from some countries, including Germany. Without a reform deal, Greece stands to lose all remaining funds when its bailout expires in the middle of the year. Relations have been tense between Greece and its creditors ever since Prime Minister Alexis Tsipras took office in January on a platform of ending bailout-related austerity measures. But the pace of negotiations has improved following changes to the Greek team last month, the ministers said. "There is no haggling about procedure any more," noted Luxembourg Finance Minister Pierre Gramegna. Progress has been made on issues including taxation, said EU Economy Commissioner Pierre Moscovici, while adding that differences remain in the areas of pension and labour market reforms. Ahead of Monday's talks, several ministers expressed their frustration at the drawn-out negotiations. "This is not a ball game," said German Finance Minister Wolfgang Schaeuble, who met his Greek counterpart, Yanis Varoufakis, ahead of the Eurogroup talks, according to Greek media. "We want to help Greece. But Greece must do its part," Schaeuble added. Irish Finance Minister Michael Noonan expressed "disappointment" at the lack of progress since February 20, when the new leftist Greek government was given four months to renegotiate its bailout-related reform programme. Many of the measures being negotiated are unpopular with the Greek public, and with the far-left factions of Tsipras' government. Greece could hold a referendum on reforms if there is no sufficient support within the government, Varoufakis said, adding that it was ultimately a decision for the president of the republic. "That could maybe even be a correct measure - to let the Greek people decide whether they are prepared to accept what is necessary," Schaeuble said. But Dijsselbloem warned of "time constraints." Athens must not only agree to reforms but must also implement them in order to receive any further bailout disbursements, he noted. "Hopefully we reach an agreement before time runs out or before money runs out," the Eurogroup chief said. "The difficulty now is that people are getting concerned, including myself, about the liquidity situation in Greece," Noonan said earlier Monday. Athens made a 756-milion-euro loan repayment to the IMF on Monday, hours ahead of a Tuesday deadline, Greek state radio reported. It is one of a series of debt redemption tranches that have raised concerns about Greece's ability to keep paying its bills. "The liquidity issue is a terribly urgent issue," Varoufakis said after the talks. The country has received a total of 240 billion euros in international rescue packages since 2010.