US President George W. Bush wrapped up a tour of the Middle East on Wednesday after failing to win full backing from Arab allies for his efforts to seal a deal on Israel and isolate Iran.

Bush made only a flying visit to Egypt for talks with President Hosni Mubarak, who welcomed the US leader in the Red Sea resort of Sharm el-Sheikh without ceremony in a sign of cooling ties between the two allies.

Bush called on Egypt to take a leading role in boosting democracy in the region.

"You have taken steps towards economic openness... and democratic reform," Bush told President Hosni Mubarak in front of reporters in Sharm el-Sheikh.

"My hope is that the Egyptian government will build on these important steps and give the people of this proud nation a greater voice in your future," he said.

After their meeting, Bush again took aim at Iran -- this time over its alleged interference in Lebanon.

The three-hour stop was the final leg of a tour which has seen Bush try to drum up support for his goal of an Israeli-Palestinian peace deal by the time he leaves office in January 2009 as well as Washington's face-off with Iran.

Relations with Egypt have faltered over Washington's criticism of Cairo's perceived failure to secure its border with the Gaza Strip, now run by the democratically elected Hamas movement which Washington and Tel Aviv call ‘terrorist’ for using armed resistance to liberate Palestinian land illegally occupied by the Israelis.

US Secretary of State Condoleezza Rice has, along with Israel, urged Cairo to do more to stop arms smuggling into the impoverished Palestinian territory.

The US Congress last month froze 100 million dollars in aid until Rice could certify that Cairo was doing enough to stem the arms flow.

Egypt, the most populous Arab country, was the first Arab state to sign a peace treaty with Israel in 1979 and has frequently acted as a peace mediator, but relations remain tense.

Protesters set fire to American flags in Cairo while the opposition Al-Ahaly newspaper told the US leader simply to "Get out."

Bush launched a new attack on Iran, telling Tehran and its close regional ally Syria to stop "interfering" in the affairs of Lebanon and urged the country to vote for a new president.

His comments came a day after three people were killed in an attack on a US embassy vehicle in Beirut.

In Saudi Arabia Bush faced difficulty in convincing his hosts to wholeheartedly support the twin pillars of his tour -- greater backing for a Middle East deal and a willingness to confront the "threat" of Iran.

Saudi Foreign Minister Saud al-Faisal gave a cool response to Bush's call for Arab states to "reach out" to Israel, which has signed peace treaties only with Egypt and Jordan.

"I don't know what more outreach we can give to the Israelis," he said.

On Iran, Faisal said: "Iran is a neighbouring country, an important country in the region. Naturally we have nothing bad against Iran."

Saudi Arabia, like other Gulf states, is determined to avoid further conflict after the 2003 US-led invasion of Iraq, which served to strengthen Iran.

Bush reiterated his warning that "all options are on the table" over Iran, and appeared to distance himself from what he called an "independent" US intelligence finding widely seen as dousing the likelihood of armed confrontation with Iran.

"I just made it clear that all options are on the table, but I'd like to solve this diplomatically -- and think we can," Bush said of talks with Saudi King Abdullah.

The US president said he told his host he still viewed Iran as "a threat" despite last month's US National Intelligence Estimate, which concluded that Tehran had shelved its nuclear weapons program in 2003.

The NIE, the consensus finding of all 16 US spy agencies, undermined the Bush administration's claim that the Islamic republic was actively seeking to get an atomic arsenal -- though it also noted that Tehran has refused to suspend uranium enrichment, which can be a key step in that direction.

"I defended our intelligence services, but made it clear that they're an independent agency; that they come to conclusions separate from what I may or may not want," said the president.

Bush said he had also told the king that the Iranians "were a threat, they are a threat, and they will be a threat if we don't work together to stop their enrichment."

Citing an anonymous senior US administration official, Newsweek magazine reported Monday that Bush had all but disowned the NIE in talks with Israeli Prime Minister Ehud Olmert.

The other main thrust of Bush's Middle East visit was to bolster revived peace talks between Israel and the Palestinians.

But despite his confident prediction in Jerusalem last week of a signed peace treaty within a year, the conflict suffered its deadliest single day of violence in 12 months on Tuesday when Israeli troops killed 19 Palestinians in the Gaza Strip.

The violence continued on Wednesday with three civilians including a teenager killed by an Israeli air strike in the heart of the Gaza Strip.