UNITED NATIONS – The Australian chairman of the U.N. Security Council's Iran sanctions committee on Thursday urged the United Nations' 193 member states to continue enforcing U.N. sanctions against Tehran over its nuclear program.

Australia's U.N. Ambassador Gary Quinlan told the 15-nation Security Council that a Nov. 24 interim deal between Iran and six world powers, which offers Iran limited sanctions relief in exchange for curbs on its nuclear program, did not affect countries' legal obligations to implement U.N. measures.

"The Security Council measures ... remain in effect; and States have an obligation to implement them duly," Quinlan said in his latest 90-day report. "It is only by a Security Council decision that these measures can be modified or terminated, and, until then, member states are obligated to enforce them."

The council has imposed four rounds of U.N. sanctions on Iran for refusing to halt its nuclear enrichment program and other sensitive atomic activities that Western powers and their allies fear could help Iran to obtain the capability to produce weapons. More draconian U.S. and European Union sanctions, built around the U.N. measures, have choked Iran's economy.

Tehran denies pursuing an atomic weapons capability and has refused to halt its program, though it did agree to temporary limitations on it during the Geneva talks last month.

Quinlan said that countries continue to report suspected violations of the U.N. sanctions. He said one country – which diplomats told Reuters was Singapore – seized goods suspected of violating U.N. sanctions last month and is investigating the matter with the U.N. Panel of Experts, a group that monitors compliance with the sanctions regime.

Quinlan also told the council that another member state – which diplomats identified as Mauritius – informed the sanctions committee last month that it was investigating "an alleged connection between an Iranian national and a company registered in the reporting State" regarding possible sanctions violations and had sought help from the committee.

The Security Council discussed the sanctions committee's report hours after the U.S. Treasury Department announced that it had blacklisted several additional companies and individuals for supporting Iran's nuclear program.

In his remarks to the council, Russian U.N. Ambassador Vitaly Churkin repeated Moscow's criticism that unilateral sanctions are wrong and should be ended. Russia and China, which maintain close commercial ties with Tehran, have said they only recognize U.N. sanctions, not U.S. and EU measures.

The five permanent U.N. Security Council members plus Germany aim to negotiate a long-term deal with Iran by late next year to end the decade-long nuclear standoff.