Haniyeh told Sheikh Tamim bin Hamad al-Thani of Qatar to update him on the unity deal signed Wednesday, Ma’an reported.
Sheikh Tamim said the move would be met with the complete support of Qatar.
Haniyeh also spoke with Turkish Foreign Minister Ahmet Davutoglu, who asserted that Turkey would "strongly support the reconciliation agreement and offer all humanitarian aid."
Interim Tunisian President Moncef Marzouki also congratulated the Palestinians for reaching a reconciliation agreement and promised that Tunisia would provide political support.
The Tunisian official said the deal was a remarkable accomplishment for the Palestinian people.
PLO and Hamas representatives announced an historic unity deal on Wednesday to bring to an end more than seven years of political division between the main Palestinian political parties.
The deal set a timetable of five weeks to form a unity government, which would hold presidential and parliamentary elections within six months.
The announcement was immediately criticized by Israel and the United States, with Israel’s security cabinet to meet Thursday to weigh its response to the deal.
Israeli Prime Minister Benjamin Netanyahu reacted angrily to the agreement, accusing President Mahmoud Abbas of choosing "Hamas, not peace".
On Wednesday, the United States warned that the deal between the Palestinian leadership and Hamas threatened to scupper any chance of rescuing the talks.
"It’s hard to see how Israel can be expected to negotiate with a government that does not believe in its right to exist," State Department Spokeswoman Jen Psaki said.
PLO official Saeb Erekat slammed Israel’s response to the unity deal, saying, "Netanyahu and his government are using Palestinian division as an excuse not to make peace."
"During the past nine months of negotiations, Netanyahu’s government has increased settlement construction, home demolitions, killings, detentions and military raids," he said in a statement.
"And the moment we sign a national reconciliation agreement upon a single political platform that recognizes all previously-signed agreements between Palestine and Israel, Netanyahu and his government blame us for the failure of talks," he added.
