The U.S. Treasury on Wednesday imposed new sanctions on Iran leading the international efforts to curb Tehran's controversial nuclear and missile programs.

UN Resolution 1929, adopted on June 9, imposes a fourth round of sanctions against Iran and includes tougher financial controls and an expanded arms embargo.

"Today, the United States is taking our first steps to implement and build on that [UN] resolution," U.S. Treasury Secretary Timothy Geithner told a news briefing.

"We are adding to our list of sanctioned entities a number of institutions and individuals who are helping Iran to fund nuclear and missile programs and to evade international sanctions," he said.

The new additions to the U.S. "blacklist" include Post Bank of Iran, Islamic Revolutionary Guard Corps (IRGC) entities and individuals, and five Islamic Republic of Iran Shipping Lines (IRISL) front companies.

The U.S. Treasury also identified 22 petroleum, energy and insurance companies as owned or controlled by the Iranian government, which puts them off limits to U.S. companies under the existing general trade embargo.

Geithner said that the United States planned more actions to increase financial pressure on Iran in the coming weeks and Washington expected similar measures from other countries in the near future.

"This is not something the United States can do alone. We need other countries to move with us," he said.

Iran has been under international pressure to halt uranium enrichment, needed both for electricity generation and weapons production. Tehran has repeatedly rejected the demand, insisting it is pursuing a purely civilian program

The pressure on Iran increased in February when Tehran announced it had begun enriching uranium to 20% in lieu of an agreement on an exchange that would provide it with fuel for a research reactor.

WASHINGTON, June 17 (RIA Novosti)