Greek Prime Minister Alexis Tsipras on Tuesday said he was confident that tough negotiations with his country's EU-IMF creditors would reach a deal by early May.

"Our goal... is to reach a first agreement this week if possible, or next week at the latest," Tsipras said in a late night interview with Greece's Star TV.

"I believe we are close," he said.

Greece has been trying to negotiate a deal that would unlock 7.2 billion euros ($7.8 billion) in remaining EU-IMF bailout money that the debt-ridden country needs to avoid default and a possible exit from the euro.

But the Tsipras government, elected in January on an anti-austerity ticket, has resisted pressure to continue with a policy of cuts in return for the cash.

Tsipras said that if his government was pressured by Greece's creditors into a deal conflicting with its electoral programme, he would put the issue to a referendum.

"If I end up with a deal beyond the limits (of my mandate), I have no other option, the people will decide," he said.

"However, there will be no need for a referendum as there will be a deal... I am convinced we will not reach that point," he argued.

By way of compromise, the PM on Tuesday said his government was prepared to consider a number of privatisations.

Tsipras said the Greek state sought to enter partnership agreements for a number of key projects, including the management of the port of Piraeus which keenly interests China.

"These will be our concessions if there is a deal," he said.

Tsipras on Monday reshuffled his negotiating team after another high-level meeting of European finance ministers in Riga ended in failure.

He said there was a need for "better coordination" with technical experts representing Greece's international creditors, insisting that Athens had "nothing to hide."

Tsipras defended his embattled Finance Minister Yanis Varoufakis, whose flamboyant style has reportedly irritated his European peers, calling him an "important asset" to the government.

But he noted that the negotiations "are always the responsibility of the prime minister."