A split has emerged between richer and poorer nations over flight security at the first conference dedicated to the issue held by the International Civil Aviation Organization.

The United States says every country needs to adopt the same high standards of security, but developing countries want security measures depending on the perceived level of threat.

They also expressed concern about the cost of the measures.

The organisation's president, Assad Kotaite, said each country should undergo a mandatory audit of all its security arrangements.

He said poorer countries would get financial help to make any necessary improvements.

But so far even Washington has failed to make any firm commitments on how much support it's willing to provide.

From the newsroom of the BBC World Service