Russia called Thursday for the closing of the Turkey-Syrian border to prevent the Islamic State and the Al-Nusra Front extremist groups from receiving foreign fighters and weapons into Syria — and from exporting oil, artifacts and other goods.

Russia's U.N. Ambassador Vitaly Churkin told a Security Council meeting on "countering terrorism" that members should also think about imposing a complete trade and economic embargo against the Islamic State group.

Churkin said in a recent letter to the council that Turkey is the main supplier of weapons and ammunition to IS fighters and that $1.9 million worth of explosives and industrial chemicals were smuggled across Turkey's border to extremist groups. Turkey's U.N. Mission rejected the allegations as "baseless."

Churkin accused Turkey on Thursday of "complacency or inaction" in allowing fighters and weapons to cross into Syria and the bulk of IS oil to be exported along with cultural artifacts.

"If Turkey feels that it is doing everything necessary to curtail the flows of supplies to terrorists, this could be corroborated by independent monitors," he said.

Churkin called on the Turkish government "on a voluntary basis" to invite international observers to its borders with Syria and the port of Ceyhan.

Secretary-General Ban Ki-moon told the Security Council that more than 30,000 people from all over the world have joined IS campaigns in Iraq and Syria. He urged member states "to take more concrete steps to stop fundraising through the smuggling of oil and gas, the illicit trade of cultural artifacts, kidnapping for ransom and donations from abroad."

Russia and China introduced a draft U.N. resolution Wednesday aimed at preventing "terrorists" from preparing or using chemical weapons in Syria.

Churkin told the council Thursday that fighters from various radical groups have used "toxic poisonous substances" this year, singling out a known case of IS using mustard gas in Deir el-Zour.

He said the draft resolution fills a gap in council resolutions and expressed hope for its speedy adoption.

The draft resolution would require countries — especially Syria's neighbors Turkey and Iraq — to immediately report any actions by extremist groups to transfer, develop or acquire chemical weapons to the Security Council and to an international body charged with establishing who is responsible for chemical attacks in Syria.

The draft would also require that body — the Joint Investigative Mechanism or JIM — to monitor any alleged activities and report monthly to the Security Council.

A Security Council diplomat, speaking on condition of anonymity because discussions about the draft resolution were private, questioned any monitoring by the JIM, which has a very small staff. The diplomat suggested Russia might be trying to divert the JIM from determining responsibility for seven alleged chemical attacks by a September deadline, noting that the Syrian government, Moscow's close ally, has been accused in several cases.