The United Nations Security Council (UNSC) Resolutions specify prohibitions of certain goods  from orto the following countries:
Al-Qaida and the Taliban
Côte d'Ivoire
Democratic People’s Republic of Korea (North Korea)Democratic Republic of Congo
Eritrea
Iran
Iraq
Lebanon
Liberia 
Libya
Somalia
Sudan

For All Countries listed above:
Arms embargo, including embargoes on weapons, ammunition, military vehicles, military equipment and paramilitary equipment, and spare parts of these items, are imposed on these countries.

For Côte d'Ivoire:
In addition, for Côte d'Ivoire, the UNSC has imposed prohibitions on rough diamonds.

For DPRK:
For DPRK, the UNSC has imposed prohibitions on specified items under the Australia Group (AG) Common Control Lists, Missile Technology Control Regime (MTCR) Equipment, Software and Technology Annex, and the Nuclear Suppliers Group (NSG) Guidelines, as well as luxury goods.

For Iran:
For Iran, the UNSC has imposed prohibitions on specified items under the MTCR Equipment, Software and Technology Annex, and the NSG Guidelines.

Please refer to the links for the lists of prohibited goods (Imports, Exports, Transhipment and Good in Transit)  

Advice to Traders
Traders are advised to refer to the webpage of the UNSC Sanctions Committees for updates on UNSC Resolutions made under Chapter VII of the UN Charter at: http://www.un.org/sc/committees/index.shtml. Under Regulation 6(1)(b) of the Regulation of Imports and Exports Regulations (RIER), importation into, exportation from, transhipment in or transit through Singapore of any goods which will contravene the decisions of the UNSC in resolutions made under Chapter VII of the UN Charter are prohibited.

Traders are also required to exercise due diligence to ensure that any  goods or technology to be exported or transferred to consignees or end-users, are not sanctioned by the UNSC, and are approved by the supplying countries, if these goods or technology are also controlled by their respective authorities.

Clarification on TradeNet^® Permit Application Requirements
Besides complying with the general permit requirements for importation into Singapore, and exportation from, transhipment and bringing in transit of goods through Singapore, traders are required to submit the TradeNet^® permit applications at least 3 working days before the intended date of shipment from/to Singapore, for the import or export of any goods from/to the DPRK and Iran.

All traders who intend to import, export, tranship or bring in transit goods which are permitted under the exceptions outlined in the UNSC Resolutions, are also required to submit the TradeNet® permit declarations prior to the shipments.

Generally, supporting documents required will include the following:
-Commercial Invoice
-Bill of Lading / House Bill of Lading or Master Air WayBill / House Air WayBill
-Packing List
-End-User Certificate

Please fax these supporting documents to Singapore Customs at Fax No. 6337 2061.