Iran's largest shipping line on Thursday dismissed U.S. sanctions against it and rejected American accusations that its ships delivered arms and other military-related cargo to Iran's military.

The Islamic Republic of Iran Shipping Lines said the sanctions targeting it and its affiliates around the globe will be ineffective because the company has no dealings with American companies and no bank accounts or assets in the U.S. However, in announcing the sanctions Wednesday, U.S. officials said they would also seek to discourage international companies from doing business with the Iranian company.

The U.S. order freezes any bank accounts or other financial assets belonging to the shipping line or its 18 related companies that are found in the United States. Americans are also barred from doing business with the companies.

The United States alleges that the Iranian company facilitated shipments of military-related cargo destined for Iran's Defense Ministry and Armed Forces Logistics. The U.S. also alleges the company falsified documents to conceal its cargo.

The shipping line called the accusations "sheer lies." The company said it had been state-controlled but is now publicly owned with thousands of shareholders and that it operates according to international regulations. The government still controls a 49-percent stake in the company.

The company said all consignments carried by its ships have been verified by authorities in departing and destination ports.

The U.S. restrictions are the latest effort to put financial pressure on Iran, which the United States accuses of bankrolling terrorism and seeking a nuclear bomb. The United States has already imposed sanctions on several state-run Iranian banks and businesses along with elements of its Defense Ministry and Revolutionary Guards Corps.

There are also three sets of U.N. sanctions in place against Iran because of its refusal to suspend parts of its nuclear program, which Iran says is meant only for peaceful purposes such as energy production.

Calls to Iranian government officials seeking comment were not returned Thursday, the start of the weekend in Iran.

According to the shipping line's Web site, the company owns 91 ships operating in ports in the Persian Gulf, Far East, Europe, India and the Caspian Sea. Its affiliated companies have about 40 ships.