U.S. Secretary of State John Kerry and Palestinian President Mahmoud Abbas met for unplanned talks on Monday afternoon, as part of their coinciding visits to Saudi Arabia.

Abbas' own trip to the capital Riyadh to meet King Abdullah was unexpected, and may have been coordinated to overlap with Kerry's.

The lunch meeting, which was added to Kerry's schedule at the last-minute on Monday morning, focused on efforts to resume the diplomatic process between Israel and the Palestinians and on U.S. President Barack Obama's upcoming visit to the region.

Kerry was supposed to have come to Jerusalem and Ramallah during his Middle East tour this week, his first official trip abroad as secretary of state, but canceled the visit at the request of the White House, apparently in light of the fact that Israeli Prime Minister Benjamin Netanyahu has still not managed to form a coalition government. He will accompany President Barack Obama to Israel, the Palestinian territories, and Jordan later this month.

Kerry arrived in Saudi Arabia following a visit to Egypt, as part of his 10-day maiden overseas trip in Europe and the Middle East. He travels next to the United Arab Emirates and Qatar before returning to Washington on Wednesday. His talks with Saudi and Gulf Arab officials are expected to focus on the crisis in Syria and fears about Iran's nuclear program.

Kerry's meeting with the Palestinian president will be his first since assuming the role of U.S. secretary of state a few weeks ago. He has already met two senior Palestinian officials, chief negotiator Saeb Erekat and Fatah Central Committee member Mohammed Shatiyeh, during the latters' visit to Washington last week.

During that meeting, Erekat and Shatiyeh presented Kerry with the Palestinian stance on the renewal of negotiations with Israel, clarifying that the Palestinian Authority would first demand Israel freeze construction in West Bank settlements and release some 120 Palestinians imprisoned in Israel since before the Oslo Accords.

Kerry intends to place the Israeli-Palestinian conflict at the center of his diplomatic activities as secretary of state and to strive to achieve a breakthrough agreement between the two sides during Obama's second term in office, according to an assessment of well-placed sources in Washington and New York reported in Haaretz last week.

In his confirmation hearings before the Senate Foreign Relations Committee in January, Kerry said the Israeli-Palestinian issue insinuated itself into every Middle Eastern issue.

"So much of what we aspire to achieve and what we need to do globally, what we need to do in the Maghreb and South Asia, South Central Asia, throughout the Gulf, all of this is tied to what can or doesn't happen with respect to Israel-Palestine," he said. "And in some places it's used as an excuse. In other places it's a genuine, deeply felt challenge."