JERUSALEM (AP) — As Israeli-Hamas violence flared, President Barack Obama’s new Mideast envoy promised on Wednesday a vigorous push for peace, saying Gaza militants must end their weapons smuggling and the blockaded borders must be pried open if a cease-fire is to take hold. George Mitchell held his first round of talks with regional leaders to determine the next steps the Obama administration would take toward reviving peace negotiations following Israel’s blistering military offensive against Gaza’s Islamic Hamas rulers.