United Nations: UN Secretary General Ban Ki-moon has urged Iran not to block the Strait of Hormuz, saying it is important for international trade and commerce.

Ban, who spoke at his first press conference on Wednesday since he began his second five-year term Jan 1, said: "This is a very important area for international trade and commerce."

"The free passage of any ships in open seas should be respected and protected in accordance with relevant provisions of the Law of the Sea," he said.

Twenty percent of the world's annual oil shipments pass through the Strait. Iran had threatened to close the Strait after the West decided to punish Tehran with more sanctions over its controversial nuclear program.

Last Monday, the foreign ministers of the European Union banned imports of oil from that country. It will take effect from July 1.