It was a brief but significant gesture: in the hubbub of the Gaza donor’s conference in Egypt, Hillary Clinton, the US Secretary of State, shook hands and exchanged a few words yesterday with Walid Mouallem, her Syrian counterpart.

In the Middle East, where even the slightest gesture is closely scrutinised, the brief encounter was seen as a sign that Washington was prepared to mend fences with Syria, whose leader, Bashar Assad, was treated as a pariah by the Bush Administration.

Mr Mouallem said afterwards that the meeting “was short but very pleasant”, and that he was “happy it happened”. With the strict protocols at summits, such encounters rarely happen by chance; they are more frequently designed to send subtle but powerful messages.

The Syrian Foreign Minister was standing at the door to the banquet room as delegates filed in for lunch at the conference to pledge more than $5 billion (£3.6 billion) for the reconstruction of Gaza. Mrs Clinton, on her first official trip to the region, had just promised to breathe new life into the peace process. She stopped in front of Mr Mouallem, shook his hand and exchanged a few words with him.

The meeting was all the more significant as Mrs Clinton had just told Abdullah bin Zayed al-Nahyan, the United Arab Emirates Foreign Minister, that she doubted that Iran – Syria’s main ally in the region – would respond to President Obama’s offer to engage with it after years of enmity. “We’re under no illusions,” Mrs Clinton said, according to an aide. “Our eyes are wide open on Iran.”

Admiral Mike Mullen, the chairman of the US Joint Chiefs of Staff, said at the weekend that Iran had enough uranium to complete its nuclear weapons programme – an ambition Tehran has always denied. “We think they do, quite frankly,” the admiral said. “And Iran having nuclear weapons, I’ve believed for a long time, is a very, very bad outcome – for the region and for the world.”

If Iran does not respond to US overtures, the new Administration may try to lure Syria away from its partner, opening the door to a return to the diplomatic fold at a time when Syria’s economy is suffering from years of isolation.

Israel, which sees Iran as its main threat, has also made moves in that direction, opening indirect peace talks through Turkey, which remained on track even after an Israeli raid on a suspected Syrian nuclear facility in 2007. One of Iran’s key methods of attacking Israel is through its Lebanese proxy, Hezbollah, which it trains, funds and arms. Much of the logistical support goes through Syria, making a deal with Damascus even more alluring to Israel and the US.

Earlier this month several leading US congressmen, including Senator John Kerry, who ran against George Bush in the 2004 presidential elections, visited Damascus for talks with President Assad.

Last week Imad Moustapha, the Syrian Ambassador to Washington, held what he described as “very constructive” talks with Jeffrey Feltman, one of Mrs Clinton’s deputies and a former US Ambassador to Lebanon.

“We believe that this meeting has explored possibilities between Syria and the United States to engage on a diplomatic and political level and also to discuss all issues of mutual concern,” the Syrian Ambassador said afterwards.

“We think this is a first step and we believe there will be many further meetings.” Many analysts believe that the new Israeli Government, led by the hawkish Binyamin Netanyahu, may concentrate on a peace deal with Syria rather than the Palestinians.

Times Recommends

• Should Knox’s trial even have reached the courtroom?
• 'Was it real?' The US bailout nightmare
• Iranian opposition plays the long game