Wrapping up a 24-hour visit to Istanbul, U.S. Secretary of State John Kerry on Sunday sought to cement and speed up an improvement in relations between Turkey and Israel as well as explore new ways to re-launch Mideast peace efforts.President Barack Obama has made both issues foreign policy priorities for his second term and Kerry was pushing them in meetings with Palestinian leader Mahmoud Abbas and Turkish Foreign Minister Ahmet Davutoglu.On a trip to Israel last month, Mr. Obama secured a pledge from Turkish and Israeli leaders to normalize ties that broke down after a 2010 Israeli raid on a Gaza-bound aid flotilla that killed eight Turks and a Turkish-American. However, the rapprochement has been slow, sparking concerns that Turkey may be backsliding on its commitment.U.S. officials say they are hopeful that a meeting this week of Israeli and Turkish diplomats to discuss Israeli compensation for victims of the flotilla raid will jumpstart the process of restoring full diplomatic relations and exchanging ambassadors between the two countries that Washington sees as key strategic partners in the volatile Middle East.Turkey’s Prime Minister Recep Tayyip Erdogan is due to visit Mr. Obama at the White House on May 16 and U.S. officials are keen to see substantive process by then.With Mr. Abbas, Mr. Kerry was talking about ways to improve the Palestinians’ living conditions as a confidence-building measure to improve the atmosphere for a resumption in stalled peace talks with Israel.Mr. Kerry has said he fears there is only a two-or three-year window of opportunity to reach a deal on a two-state solution that would end the decades-old Israeli-Palestinian conflict and wants to move as quickly as possible. He has met with Abbas and Israeli Prime Minister Benjamin Netanyahu several times already to that end since becoming secretary of state.Mr. Kerry was in Istanbul primarily to attend an international conference on Syria that began on Saturday afternoon and stretched into early Sunday morning as participants debated how best to boost aid to rebels trying to topple Syrian President Bashar Assad’s regime.At the conference, he announced that the Obama administration would double its non-lethal assistance to the Syrian opposition with an additional $123 million in supplies that could include for the first time armoured vehicles, body armour, night vision goggles and other defensive military supplies.The additional aid, which brings total non-lethal U.S. assistance to the opposition to $250 million since the fighting began more than two years ago, “underscores the United States’ firm support for a political solution to the crisis in Syria and for the opposition’s advancement of an inclusive, tolerant vision for a post-Assad Syria,” Mr. Kerry said.The U.S. pledge was the only tangible, public offer of new international support at the meeting of the foreign ministers of the 11 main countries supporting the opposition and fell well short of what the opposition has been appealing for- weapons and direct military intervention to stop the violence that has killed more than 70,000 people.The Syrian National Coalition is seeking drone strikes on sites from which the regime has fired missiles, the imposition of no-fly zones and protected humanitarian corridors to ensure the safety of civilians.While pleased with the U.S. moves, the opposition appeared deeply disappointed, especially as it lost some ground in the latest clashes with Syrian troops backed by pro-government gunmen capturing at least one village in a strategic area near the Lebanese border.“We appreciate the limited support given by the international community, but it is not sufficient,” it said in a statement released at the end of the conference. “We call on the international community to be more forthcoming and unreserved to fulfill its responsibilities in extending support that is needed by the Syrian people.”With the exception of the United States, none of the participants offered new assistance, although European nations are considering changes to an arms embargo that would allow weapons transfers to the Syrian opposition. But European Union action is unlikely before the current embargo is set to expire in late May.Mr. Obama has said he has no plans to send weapons or give lethal aid to the rebels, despite pressure from Congress, some administration advisers and the appeals from opposition.There are no plans to change that policy, although U.S. officials say they are not opposed to other countries sending arms, as long as the recipients have been properly vetted.