"I want to assure you that we will support you as the lawful leader of the Palestinian people. We are certain that you will do everything to secure unity," Putin told Abbas at the start of key talks in the Kremlin.

Abbas said he would make "every possible effort" for unity following a bloody takeover of the Gaza Strip last month by the Islamist radical movement Hamas opposed to his Fatah party.

Russia has carved out a unique position in Middle East diplomacy by maintaining contacts both with Fatah and Hamas, which is considered a terrorist group by the European Union and the United States.

Foreign Minister Sergei Lavrov stressed in his Monday meeting with Abbas "the need to restore Palestinian unity through dialogue between all political forces," the ministry said in a statement.

Speaking in Gaza on Monday, sacked Palestinian premier Ismail Haniya said that his Hamas movement would welcome Russian mediation "to fill the gap between us and Fatah, to put an end to the crisis."

But Abbas was expected to press Moscow to cut contacts with Hamas during his three-day visit, which ends Tuesday, though the Russian foreign ministry on Monday gave no indication it would do so.

Abbas and the newly-appointed Palestinian prime minister he backs, Salam Fayyad, have ruled out any dialogue with Hamas as long as the movement maintains its takeover of the Gaza Strip.

Ahead of the meeting in the Kremlin, Abbas said that he was "eager" for the talks with Putin in order to find ways in which Russia could help end the "internal political deadlock" in the Palestinian territories.

The Palestinian president has declined to openly criticise Russia for engaging with Hamas, telling Russian daily Nezavisimaya Gazeta in an interview published Tuesday that this was "Russia's matter as a sovereign state."

Putin has worked steadily to boost Russia's presence in the Middle East, though Russia's official contacts with Hamas -- including a Moscow visit by the group's chief Khaled Meshaal in February -- have been criticised in the West.

The Palestinian president's visit comes amid efforts to inject new energy into the Middle East Quartet, which recently appointed former British prime minister Tony Blair as its envoy.

This week's talks also precede a Middle East conference scheduled for September at the initiative of US President George W. Bush.