Turkey's government, accused of siding with Hamas during Israel's Gaza offensive, has called on the Islamist group to use peaceful means to achieve its aims rather than armed struggle, its foreign minister said.

The government has come under criticism for the strong rhetoric it used against Israel during the offensive in the Gaza strip. Turkish opposition parties, ex-diplomats and columnists have accused the government of taking a pro-Hamas stance.

"Hamas should make a decision. Do they want to be an armed organisation or a political movement?," Foreign Minister Ali Babacan told Milliyet and Radikal newspapers in an interview published today.

"Our suggestion is that they work within the framework of the political system. The party supported by Hamas got 44 per cent of the votes in the last elections. It is impossible to ignore this base," he said.

Turkey, a predominantly Muslim but secular country that historically has had good ties with Israel and the Arab world, played a role in helping broker an end to the offensive this month, particularly by lobbying Hamas to declare a unilateral cease-fire.

Turkish Prime Minister Tayyip Erdogan called Israel's operations, launched with the aim of ending Hamas's cross-border rocket attacks, "a crime against humanity," deploring what he saw as excessive force, and he suggested Israel be barred from the United Nations.

His remarks shocked Israel and were interpreted by some political observers as a bid to shore up support ahead of local elections in March with an electorate deeply sympathetic to Palestinians.

"Babacan's approach and his carefully chosen words show that Ankara which is criticised of being pro-Hamas and even a speaker for Hamas, is now moving towards the centre," Fikret Bila, a prominent columnist said.

Turkish analysts say the government's stance during the Gaza conflict may have weakened its role as a mediator in the Middle East. Turkey led indirect peace talks between Israel and Syria.

"We criticised Israel's operations from the very first day. We received written and oral statements from worried Jewish organisations, especially in the United States. They told us anti-Semitism would gain momentum and Turkish-Israeli relations would suffer," Babacan said.

"We take these reactions into consideration. Turkish-Israeli relations may get harmed in the short term but I do not expect negative results in the medium and long term," he said.