"Iran has on numerous occasions shown flexibility, but it has been responded with consecutive Security Council resolutions," Director-General of the Department for Political and International Studies of the Iranian Foreign Ministry Mostafa Dolatyar said, addressing a seminar on nuclear non-proliferation in Moscow on Sunday.
"The United States and its allies have adopted hostile approaches and unconstructive positions in the past years, thereby killing the chance of obtaining any agreement (on Iran's nuclear energy program)," he added.
"Over these years, the US has neglected all the positive steps Iran has taken… throughout its negotiations with theGroup5+1 (the US, France, Britain, Russia, and China plus Germany) and the European sides have regrettably followed in the footsteps of Washington's hostile policy against Tehran," he said.
Dolatyar called for the return of Iran's nuclear case from the United Nation's Security Council to the International Atomic Energy Agency (IAEA).
Washington and its Western allies accuse Iran of trying to develop nuclear weapons under the cover of a civilian nuclear program, while they have never presented any corroborative evidence to substantiate their allegations. Iran denies the charges and insists that its nuclear program is for peaceful purposes only.
Despite the rules enshrined in the Non-Proliferation Treaty (NPT) entitling every member state, including Iran, to the right of uranium enrichment, Tehran is now under four rounds of UN Security Council sanctions for turning down West's calls to give up its right of uranium enrichment.
Tehran has dismissed the West's demand as politically tainted and illogical, stressing that sanctions and pressures merely consolidate Iranians' national resolve to continue the path.
Political observers believe that the United States has remained at loggerheads with Iran mainly over the independent and home-grown nature of Tehran's nuclear technology, which gives the Islamic Republic the potential to turn into a world power and a role model for the other third-world countries. Washington has laid much pressure on Iran to make it give up the most sensitive and advanced part of the technology, which is uranium enrichment, a process used for producing nuclear fuel for power plants.