A newly formed deal between Iran and world powers does not guarantee the lifting of economic sanctions, a western diplomat involved in the talks said on Tuesday, rejecting Israeli accusations, according to which talks provide Iran with more time to advance its nuclear weapons program.

The diplomat's comments came following an announcement by Yukiya Amano, head of the International Atomic Energy Agency (IAEA), in which he indicated that he had reached an agreement with Iran on probing suspected work on atomic weapons, adding that he hoped the agreement would "be signed quite soon."

Amano's announcement was met with skepticism in Israel, with a senior official warning of Tehran's history of ignoring agreements, adding that the "IAEA's last report refers to the military intentions of Iran's nuclear program. North Korea has also reached agreements with the IAEA in the past, and this ended in two nuclear attempts."

Speaking to Haaretz later Tuesday, a western diplomat involved in the talks with Iran, due to begin Wednesday in Baghdad, said that "for the first time, it is clear that the Iranians are willing to engage in concrete issues and talk about the uranium enrichment."

The diplomat rejected claims being made in Israel that the talks are simply allowing the Iranians more time to proceed in developing nuclear weapons, saying: "Nobody here is naïve," adding that "we know full well the history of negotiations with Iran, and their history of hiding things, but we have a responsibility to go down the diplomatic route and see if an agreement can be reached."

"There is room for skepticism, but the cynicism we are hearing from Israeli is unwarranted," he added.

The diplomat heralded the imminent agreement between the Iranians and the International Atomic Energy Agency (IAEA) on new inspections of Iran's nuclear installations, saying that "Iranian cooperation with the IAEA is sine qua non, to a framework treaty between Iran and the international community" and that there had been no promise to an easing of international sanctions on Iran in return for this agreement."

In response to Israeli accusations that the negotiators were willing to accept empty Iranian promises, the diplomat said that "we are not just taking promises and good atmosphere as proof."

"We will require concrete steps from the Iranian and we will have to see movement on the uranium issue. Without these steps, without traction on uranium enrichment, there will be no easing of the sanctions," he added.

He added that current "sanctions now are so complex and expensive to the Iranians that we can tentatively remove one or two elements while keeping most of the sanctions in place. The sanctions won't be an on-off switch but bargaining chips."

The diplomat stressed that they were demanding the Iranians concede both on the level of uranium enrichment and on the uranium that has already been enriched to 20 percent. He said also that the talks would not end in Baghdad, "but it's about a framework that will include also other aspects of the Iranian program."

Earlier Tuesday, Iran's official news agency IRNA reported that Iranian scientists had inserted a domestically made fuel rod, which contains pellets of 20 percent enriched uranium, into the core of a research nuclear reactor in Tehran.

The advance would be another step in achieving proficiency in the entire nuclear fuel cycle. Iran said in January that it had produced the first nuclear fuel rod, and that it had to find a way to make them because Western sanctions prohibit their purchase from foreign markets.