AMMAN (REUTERS) - Syrian President Bashar al-Assad on Wednesday (Nov 11) blamed United States sanctions and pressure on the United Nations as well as Syria's neighbours for the reticence of more than five million refugees who fled the conflict there to return.

"There are many hurdles," Mr Assad said, citing US sanctions at the opening of a conference in Damascus, co-hosted by Moscow, that has been boycotted by Washington, the European Union and most of Syria's neighbours that host the bulk of its 5.6 million refugees.

Of Syria's 17 million people, 5.5 million are living as refugees in the region, mostly in Turkey, and a further six million are uprooted within their own country.

Mr Assad said millions of refugees were being forced to stay in host countries by "pressure or intimidation" and that host states were enticing them financially while benefiting from international aid for them.

Western countries and all of Syria's neighbours with the exception of Lebanon say conditions are not safe for the voluntary return of refugees, many of whom fled from Russian and Syrian government bombing of their towns during the course of the decade-old conflict.

EU policy chief Josep Borrell said in a statement on Tuesday that the body had turned down an invitation to attend as "the priority at present is real action to create conditions for safe, voluntary, dignified and sustainable return of refugees and internally displaced persons to their areas of origin".