Israel said it\'s not optimistic on the results of the upcoming Iran nuclear talks set to begin tomorrow, Friday, with the P5+1 countries, Israeli official sources said Thursday. The same sources added that the stance of the US towards the upcoming talks are still anonymous to Israel which is currently staying silent regarding the talks and just watching the scene. The Israeli daily \'\'Yedioth Ahronoth\'\' said late on Wednesday that the White House appears to have toughened its stance on the issue, however Israel rejects going through what the news stories say on this issue. Israeli press revealed recently ongoing disputes between Prime Minister Benjamin Netanyahu and Defense minister Ehud Barak. Netanyahu insists that Iran as not having uranium stocks at all whereas Barak opposes the idea of Iran enriching more than 20 % Uranium. Iran\'s P5+1 round of talks is set to begin in this Saturday in Istanbul as the second round will be hosted in Baghdad. The P5+1 states are the five permanent members of the UN Security Council, US, Russia, Britain, France, China plus Germany.