<p><br /> US President Barack Obama has vowed that "extremists and rejectionists" would not derail the relaunch of Israeli-Palestinian negotiations as he opened a peace summit shadowed by Middle East violence.<br /> </p><p><br /> Wading into Middle East diplomacy in the face of deep skepticism over his chances for securing an elusive peace deal, Obama condemned as "senseless slaughter" a Hamas attack on Tuesday that killed four Jewish settlers in the occupied West Bank.<br /> </p><p><br /> "The message should go out to Hamas and everybody else who is taking credit for these heinous crimes that this is not going to stop us from not only ensuring a secure Israel but also securing a longer lasting peace," Obama told reporters.<br /> </p><p><br /> Obama said progress was made in one-on-one meetings he hosted with Israeli Prime Minister Benjamin Netanyahu and Palestinian President Mahmoud Abbas ahead of direct Israeli-Palestinian talks to be held on Thursday for the first time in 20 months.<br /> </p><p><br /> The summit marks Obama's riskiest plunge into peacemaking, not least because he wants the two sides to forge a deal within 12 months for the creation of a Palestinian state alongside a secure Israel.<br /> </p><p><br /> But Netanyahu also underscored Israel's demands that any final peace deal include security arrangements to ensure a future Palestinian state, which he says must be demilitarized and would not become an "Iranian-sponsored terror enclave."<br /> </p><p><br /> Deep distrust between the two sides is one of the biggest obstacles to Obama's quest for the so-called two-state solution that has eluded so many of his predecessors.<br /> </p>
