ISLAMABAD/WASHINGTON, April 27 -- ISLAMABAD/WASHINGTONHopes of reviving peace efforts in the US-Israeli war with Iran faltered on Sunday with President Donald Trump, who called off a planned diplomatic mission on Saturday, said Washington was open to talks only by phone, even as Iran's foreign minister Abbas Araghchi continued shuttle diplomacy across the region. Araghchi travelled between Pakistan, Oman and back to Islamabad over the weekend before departing for Moscow, where he is expected to meet Russian President Vladimir Putin. The flurry of movement underscored efforts by mediators to keep negotiations alive despite the absence of direct engagement between Washington and Tehran. Trump scrapped a planned visit by his envoys, Steve Witk...