The five permanent members of the U.N. Security Council plus Germany will discuss imposing a third round of sanctions on Iran because of its nuclear programme on Friday.
Iran has refused to stop enriching uranium and the West fears it is bent on producing atom bombs, which Tehran denies.
The United States, which will be represented by undersecretary of state for political affairs Nicholas Burns, says it wants to make progress in outlining the sanctions resolution and ministers can then decide on its timing.
Burns said he hoped Russia and China would attend the meeting with a "serious demeanour". He said the two countries, major trading partners with Iran, had effectively blocked moves towards a third sanctions resolution for six months.
The United States imposed economic sanctions last week and has not ruled out military action against Iran. Russia believes dialogue rather than more punishment is the way forward while China reacted to the American move by saying it was opposed to imposing sanctions "too rashly".
The major powers agreed in late September to delay a vote on tougher sanctions until late November at the earliest after it had received reports by the U.N. nuclear watchdog (IAEA) and a European Union negotiator.
After four days of talks with the IAEA in Tehran meant to help clear up suspicions about Iran's atomic activities, both sides expressed satisfaction, Iran's state broadcaster reported on Thursday.
Mohamed ElBaradei, head of the U.N. International Atomic Energy Agency (IAEA), is due to report in mid-November about whether Iran has answered questions about its past secret nuclear activity. ( Reuters )