Turkish President Recep Tayyip Erdogan urged Palestinians to unite amid Israel's war in Gaza following hours-long talks with Hamas chief Ismail Haniyeh in Istanbul on Saturday, his office said.

Erdogan said Palestinian unity was "vital" following the talks at the Dolmabahce palace on the banks of the Bosphorus strait, which Turkish media reports said lasted more than two and a half hours.

"The strongest response to Israel and the path to victory lie in unity and integrity," Erdogan said according to a Turkish presidency statement.

As fears of a wider regional war grow, Erdogan said recent events between Iran and Israel should not allow Israel to "gain ground and that it is important to act in a way that keeps attention on Gaza".

"Even if only I, Tayyip Erdogan, remain, I will continue as long as God gives me my life, to defend the Palestinian struggle and to be the voice of the oppressed Palestinian people," the president said Wednesday when he announced Haniyeh's visit.

Hamas has had an office in Turkey since 2011 when Turkey helped secure the agreement for the group to free Israeli soldier Gilad Shalit.

Fidan on Saturday held talks with visiting Egyptian Foreign Minister Sameh Shoukry, with both men emphasising the need to deliver more humanitarian aid to devastated Gaza where the threat of famine looms.

Turkey is one of Gaza's main humanitarian aid partners, sending 45,000 tonnes of supplies and medicine in the region.

Israel has said it is preparing an offensive against the Gazan city of Rafah and the reported Israeli attack on the Iranian province of Isfahan, following Iran's direct attack on Israel, has only clouded hopes of a peace breakthrough.