Experts and diplomats questioned some of the report's allegations.
Critics questioned the finding that 720 Somali mercenaries fought alongside Hezbollah in its July battle with Israel and that Iran shipped arms to Somalia's Council of Islamic Courts in return for access to uranium mines.
The UN also reiterated "its insistence that all member states, in particular those in the region, should refrain from any action in contravention of the arms embargo and should take all necessary steps to hold violators accountable".
Meanwhile, the US consulted UN council members on another resolution that would lift the arms embargo for a regional force.
Richard Grenell, spokesperson for the US mission, said the resolution the United States is working on is in response to a recommendation from the group monitoring the arms embargo.
"We're going to remain engaged to prevent any escalation of tensions"
Richard Grenell, US mission spokesperson
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The US supports the proposal by the Intergovernmental Authority on Development, a seven-nation East African group, to deploy an African force in Somalia, he said.
The force, totaling a battalion or two, would train and protect the transitional government, based in Baidoa, to establish a balance in Somalia that would convince the Islamists that a military victory is impossible, he said.
Diplomats said the European Union has proposed amendments that would block any of Somalia's neighbors from participating in the force.
That would prohibit participation by troops from Ethiopia, Djibouti and Kenya - but not Uganda which has volunteered troops this far.
The Europeans also want the force to be authorised for a limited period of time, the diplomats said, speaking on condition of anonymity because the US draft has not been finalised.
"We're going to remain engaged to prevent any escalation of tensions in Somalia which could lead to a wider regional conflict, and the deployment of this regional force is a step to ensure this doesn't happen," Grenell said.