Iran's top nuclear negotiator told international observers Thursday he was prepared to offer new initiatives ahead of crunch talks this weekend.

Tehran's top negotiator Saeed Jalili told the group of six world powers gathered in Istanbul for talks this Saturday that Iran is ready to hold successful and progressive talks on cooperation.

Jalili did not however elaborate on any specific plans Iran would bring to the negotiating table.

According to diplomatic sources, the United States, France, Germany, China, Russia and Britain will wait for Tehran to signal it is serious about negotiations before laying out any demands.

The onus is on them in this first meeting to demonstrate that they are serious about a negotiation over their nuclear program. If they are, we will get into detail on what that would look like, a diplomatic source told Reuters.

The talks come amid a backdrop of increasingly tough economic sanctions on Iran, which last month was cut off from the SWIFT transaction service, effectively severing the country's economic link to the global financial system.

The U.S. and EU led sanctions have also called for a boycott of Iranian oil, in a bid to stop the country pressing ahead with its uranium enrichment program.

Led by the U.S. and Israel, Western nations believe Iran is trying to assemble a nuclear weapon, something Tehran has repeatedly denied.

Iran has in the past ruled out suspending its nuclear enrichment program, a process that has civilian as well as military applications. But recently the country has hinted that it may discuss halting its higher-level enrichment work.