President Barack Obama's administration is preparing new sanctions on international companies and individuals over Iran's ballistic missile programme, sources familiar with the situation said on Wednesday.

The Wall Street Journal reported earlier that the potential sanctions would target about 12 companies and individuals in Iran, Hong Kong and the United Arab Emirates for their suspected role in developing Iran's ballistic-missile programme.

U.S. officials have said the Treasury Department retains a right under July's landmark nuclear agreement between Iran and six world powers including Washington to blacklist Iranian entities suspected of involvement in missile development, the Journal said.

Iranian officials have said the country's supreme leader would view such penalties as violating the nuclear accord.

A team of U.N. sanctions monitors said in a confidential report seen by Reuters on Dec. 15 that a medium-range Emad rocket that Iran tested on Oct. 10 was a ballistic missile capable of delivering a nuclear warhead, making it a violation of a U.N. Security Council resolution.

Diplomats have said it was possible for the sanctions committee to blacklist additional Iranian individuals or entities over the missile launch. But they said Russia and China, which have opposed the sanctions on Iran's missile programme, might block any such actions.

Tehran has disputed the Western assessment that the Emad missile was capable of delivering a nuclear warhead.

The Journal said the planned Treasury Department sanctions concerned two Iran-linked networks involved in developing the country’s missile programme and include many of the people involved.

The sanctions would prohibit U.S. or foreign nationals from conducting business with the companies. U.S. banks would also be required to freeze any assets the companies or individuals hold inside the American financial system.

Among those targeted would be UAE-based Mabrooka Trading Co LLC and its founder, Hossein Pournaghshband, for aiding Iranian state companies in acquiring carbon fibre for Iran’s missile programme, the newspaper said, citing a Treasury statement.

The Treasury is also preparing to sanction five Iranian officials at the country’s defence ministry and its subsidiaries for work on the ballistic-missile programme, according to the newspaper.

The Journal said reasons for the potential sanctions included ties the Treasury is alleging between Iran and North Korea on missile development.