Washington (CNN) -- The United States is extending sanctions against Iran, announcing Tuesday that it is targeting a number of Iranian entities accused of aiding groups such as Hezbollah, Hamas and the Taliban.
The U.S. Treasury Department said it has identified 21 entities owned or controlled by the Iranian government that help these groups and a variety of other radical groups in the Middle East.
"Iran is the primary funder of Hezbollah and has long been recognized as the most active state sponsor of terrorism," the Treasury Department said in a statement. The department identified the Islamic Revolutionary Guard Corps-Qods Force as one of the main channels used by the Iranian government for supporting terrorism "under the guise of providing reconstruction and economic development assistance or social services."
The Treasury Department said it has evidence that members of the Qods Force provide weapons and training to the Taliban.
Announcing the measures, Under Secretary for Terrorism and Financial Intelligence Stuart Levey said the United States was working with allies to make sanctions against Iran as effective as possible.
The entities targeted by the U.S. include companies in the banking, insurance and investment, mining and engineering industries owned or controlled by Iran. Several are based outside Iran, including companies based in Dusseldorf, Germany; a trading company in Japan and another based in Genoa, Italy.
A number of the entities now facing sanctions trade under the name Ascotec. Two banks based in the former Soviet republic of Belarus -- Bank Torgovoy Kapital and Onerbank ZAO -- also are targeted.
The effect of "designation," as it is known, is to prohibit any person or company in the United States from doing business with the entities listed. The U.S. Treasury says it has now designated a total of 58 Iranian entities.
Levey said the designations serve as an alert to thousands of businesses and financial institutions around the world -- and discourage them from doing business with these entities because of their association with terrorism or nuclear proliferation
"As its isolation from the international financial and commercial systems increases, the government of Iran will continue efforts to evade sanctions, including using government-owned entities around the world that are not easily identifiable as Iranian to facilitate transactions in support of their illicit activities," said Levey. "Today's identifications will mitigate the risk that such entities pose to legitimate transactions," he said.
In addition, the U.S. Treasury has designated two Iranian organizations based in Lebanon for assisting Hezbollah. One is the Iranian Committee for the Reconstruction of Lebanon (ICRL). The U.S. government says the committee "provides financial, material, and technical support to Hezbollah." The committee "has financed and facilitated Hezbollah's infrastructure and private communications network that enables the terrorist group to communicate securely," the Treasury Department said.
Another target of U.S. action is the Imam Khomeini Relief Committee Lebanon Branch.
"Iran has provided millions of dollars to the Hizballah-run branch in Lebanon since 2007. The IKRC has helped fund and operate Hizballah youth training camps, which have been used to recruit future Hizballah members and operatives," the department said.
In June, the U.S. Treasury Department announced sanctions targeting the country's nuclear and missile programs -- identifying more than 20 companies and several individuals allegedly involved with those programs.
The Treasury Department said the measures begin to implement the recent U.N. Security Council Resolution 1929 and highlight "Iran's use of its financial sector, shipping industry and Islamic Revolutionary Guards Corps to carry out and mask its proliferation activities."