Palestinian leader Mahmoud Abbas has met Israeli Foreign Minister Silvan Shalom at the UN internet summit in Tunis, an Israeli official says.
President Abbas has welcomed the agreement on Gaza's borders
They held talks for about 30 minutes with the president of Mauritania, Ely Ould Mohammed Vall, the official said.
Elsewhere, international envoy James Wolfensohn said he was contemplating quitting his role.
He said he was frustrated at his inability to persuade Israelis and Palestinians to work together.
Heads of state and representatives from the United Nations and the European Union were meeting in Tunisia for the World Summit on the Information Society (WSIS).
The unscheduled meeting of Mr Abbas and Mr Shalom comes a day after a deal was brokered by US Secretary of State Condoleezza Rice to reopen the Gaza-Egypt border on 25 November.
Israeli official Lior Ben-Dor said the Palestinian Authority president expressed his satisfaction with Tuesday's agreement, which is seen as key for Gaza's economy and Palestinian exports.
He also hoped the agreement would lead to further talks on a final peace deal.
Mr Shalom, however, raised Israel's concern with the Palestinian militant group Hamas's participation in January's parliamentary elections.
It is Mr Abbas's highest level meeting with an Israeli for months.
Tunisia broke off ties with Israel in 2000 after the outbreak of widespread Israeli-Palestinian violence knows as the second intifada. However, three Tunisian ministers were scheduled to meet Mr Shalom during his visit.
Mr Shalom was born in Tunisia, but his family left when he was a child. On Tuesday, he visited his birthplace, the port city of Gabes, with his mother who travelled from Israel with him.
Hamas had earlier criticised Mr Abbas's Palestinian Authority for having "accepted this weak accord and given the impression that it was a great accomplishment".
"This agreement does not respond to the needs of the Palestinian people," the group said in a statement.
Mr Wolfensohn had criticised Israel of foot-dragging over the deal
"It stifles the Gaza Strip and turns it into a big prison, where departures and entries are controlled by guardian countries."
Middle East envoy James Wolfensohn has said he was frustrated that Ms Rice's presence was needed to reach an agreement on the reopening of Gaza's borders.
"If you are an envoy of the Quartet you have a certain amount of possibilities in negotiations," Mr Wolfensohn told reporters.
"If you are the secretary of state of the United States, I would have to say there is a little more clout associated with it. And to push it over the edge, one needs not envoys, but secretaries of state."
Mr Wolfensohn, an Australian-born former head of the World Bank, was named by US President George W Bush as a special representative of the Middle East Quartet (the UN, Russia, EU and US) earlier this year.