Siniora told the parliament that the Arab and Muslim worlds were at a crossroads that could either lead to peace or further extremism.
He said: "Delay in finding solutions is not going to keep things as is.
"The situation is going to get more and more complicated. The way to deal with it is to go to the root causes."
He said that a fair implementation of the UN Security Council resolution which ended the Israel-Hezbollah war and a resumption of talks to create a viable Palestinian state were needed.
He later told reporters: "The EU has a very important role. Specifically the EU can and must now put pressure on the United States to play a more constructive role, which they have failed to do so far.
"It is about confidence, the people of our region have confidence in Europe and simply do not in the United States."
Siniora also demanded that Israeli troops pull-out of Lebanon immediately and called the continued Israeli occupation of Lebanese territory - including Shebaa Farms - the "mother of all ills".
He said: "In order for the current cessation of hostilities to be sustained, Israel must withdraw without further delay from the position it still occupies within Lebanon and must stop its violation of Lebanese territory."
Israel's military chief of staff said on Wednesday that disputes over how the Lebanese army and the UN peacekeepers will deal with Hezbollah fighters is holding up the troop withdrawal.
But Siniora said that the disarmament of Hezbollah could only be dealt with after Israeli withdrawal and he told a news briefing that once Israel has fully withdrawn, "there won't be any valid argument then for the continuation of weapons in the hands of Hezbollah".
He said that ensuring Lebanese territory was fully under Lebanese control would empower moderates and "pull the rug from beneath the feet of the extremists".