International donors met Monday to approve a "New Deal" for Somalia to drive its economic and political recovery after two decades of bloody civil war.

President Hassan Sheikh Mohamud faced one of "the most difficult challenges in the world", EU foreign affairs head Catherine Ashton said as they went into the meeting.

"I hope this will be a really significant moment" for Somalia, Ashton added.

Mohamud said he was "very grateful" for all the effort made on behalf of his country, highlighting four priorities among the many tasks ahead -- security, legal reform, public finances and economic recovery.

"The New Deal must deliver on the ground soon," he told delegates in an opening address.

After years of suffering, "expectations from are our people are understandably high. We must not let them down," he said.

However, in a dismissive commentary, Somalia's hardline Islamist Shebab rebels dismissed the conference as "Belgian waffle" and a waste of time.

"The billions promised will most likely be unpaid, the paltry sum given to the apostates," it said, using its term for the Somali government, "will be lost in corruption."

"It's a bit like Belgian Waffles: sweet on the outside but really has not much substance to it. They are just hollow promises of Kufr", or infidels, it said.

"Conferences never really had any meaningful impact on the ground here in Somalia and this one will be no different."

In January, Mohamud won the first formal US recognition of a Somali government since the 1991 overthrow of dictator Mohamed Siad Barre sparked a bitter civil war.

Some 50 high-level delegations from Africa, Europe and the Gulf are attending the one-day meeting in Brussels, along with aid groups and global finance institutions.

The New Deal Compact to be approved Monday sets out government priorities and future international support.

High on the agenda are plans to get one million children into school in a country that has one of the world's lowest enrollment rates -- with only four of every ten children in class.

Over the past year, the government and parliament have worked without interruption but are not yet strong enough to secure international loans and are therefore dependent on grants.

Between 2008 and 2013, the European Union provided 1.2 billion euros in aid -- 521 million euros in development cooperation and 697 million euros for security.

Most security funding went to the African Union Mission in Somalia (AMISOM), comprising some 17,000 troops and launched in 2007 with UN Security Council approval.

It props up the government in Mogadishu and has fought alongside its army, seizing a string of towns from Shebab rebels.

In recent months, however, several deadly Shebab attacks have dented confidence.

In June, a suicide commando assault on a fortified UN compound in the centre of Mogadishu killed 11.

At least 18 people were killed in Mogadishu on September 7 when two blasts rocked a popular restaurant, an attack quickly claimed by the Shebab.

With insecurity growing, in August medical aid agency Doctors Without Borders (MSF) closed all its operations in Somalia, after 22 years of working in the Horn of Africa troublespot.

As well as a military training mission in Somalia, the EU runs an anti-piracy operation off the Somali coast, where attacks on shipping have fallen steadily in the past year.

Mohamud's government came to power last September after more than a decade of transitional rule.

[Image via AFP]