That was the advice from Barack Obama to his new peace envoy George Mitchell who is on a whistle-stop tour of the Middle East.After meeting Egyptian President Hosni Mubarak later today, Mitchell will travel on to Israel, the West Bank, Jordan and Saudi Arabia. Earlier, Mitchell held talks with an old friend, EU foreign policy chief Javier Solana, also on a week of shuttle diplomacy. 75-year-old Mitchell’s trip is aimed at strengthening the fragile truce between Israel and Hamas, under pressure after an upsurge in violence over the last 24 hours. Meanwhile, Hamas leader Khaled Meshaal has once more called for Israel to lift its blockade of Gaza and re-open the crossing points. Meshaal made his appeal during talks with Syrian President Bashar al-Assad in Damascus.