George Mitchell will make his first trip to the region later this week as Washington's new Middle East envoy, for talks with Israeli and Palestinian Authority leaders. Sources in Jerusalem said they were eager to hear what Mitchell had to say, following the very positive initial contacts with both President Barack Obama and Secretary of State Hillary Clinton. Mitchell is expected to join efforts to shore up the Gaza cease-fire. However, any longer term initiatives are not anticipated until after the Israeli elections, in 16 days. Meanwhile, Defense Minister Ehud Barak met on Saturday night with Quartet envoy Tony Blair, telling him that Iran's armament plans threaten the stability of the region and the world as a whole. There was still time for sanctions to work, Barak said, stressing the need for cooperation among the West, Russia and China. At the same, he said, Israel was not taking any option off the table. Last week Obama called on Israel to open the border crossings to Gaza and on the PA - helped with funds and support through an international donors conference - to play a role along with the international community in monitoring the access points. "It will be the policy of my administration to actively and aggressively seek a lasting peace between Israel and the Palestinians, as well as between Israel and its Arab neighbors," he said. Mitchell, a former senator from Maine, is well versed in the details of regional issues having served as president Bill Clinton's envoy in 2000 and 2001, when he led a six-month fact-finding mission on the reasons behind the second intifada. The Mitchell Commission report had elements both sides praised and criticized. It urged Israel to halt all settlement activity and to stop shooting at unarmed demonstrators, and it called on the PA to stop violence and to punish those who commit it. Mitchell is best known for helping to forge the Good Friday agreement of 1998, which ended 800 years of Protestant-Catholic conflict in Ireland.