A high-ranking delegation from the U.N. nuclear agency began talks with Iran Tuesday on the country's disputed nuclear program, state media reported.

The discussions are the latest attempt by the International Atomic Energy Agency to address outstanding questions on a program that many Western countries believe is cover for weapons development, but Iran insists is focused on power generation.

"The talks will be technical and take two to three days," the official Islamic Republic News Agency quoted Iran's envoy to the IAEA, Ali Asghar Soltanieh, as saying.

IAEA Deputy Director-General Olli Heinonen is leading the U.N. delegation and Javad Vaeedi, Iran's deputy nuclear negotiator, is heading the Iranian side, the news agency said.

Soltanieh said the negotiations would be a continuation of the four previous rounds of talks between Iran and the IAEA, three of which were held in Tehran and one in Vienna where the IAEA is based.

During those meetings, Tehran expressed a willingness to answer outstanding questions related to its nuclear program but continued to refuse to suspend uranium enrichment as demanded by the U.N. The U.S. and some of its allies fear Iran is simply trying to reduce international pressure while continuing its pursuit of a nuclear weapon.

On Sunday, Iran's Foreign Ministry spokesman Mohammad Ali Hosseini said the agenda for the current talks would include P-1 and P-2 centrifuge machines, which can enrich uranium for either nuclear fuel or weapons. P-2 centrifuges are more sophisticated, consuming less electricity and producing more enriched uranium.

IAEA chief Mohamed El-Baradei praised Iran's cooperation with the agency in September as a significant step, but urged Tehran to answer all questions — including reported experiments that link enrichment and missile technology — before the end of the year. The U.S. continues to push for a more punitive sanctions against Iran but is meeting resistance from several members of the U.N. Security Council, including Russia, China and Germany.

Faced with the possibility of harsher sanctions, Tehran offered a rare concession in August and allowed IAEA inspectors to revisit a heavy-water reactor under construction outside Arak in central Iran that has been off-limits since April.

The U.N. Security Council has already slapped two sets of sanctions on Iran, mainly targeting the country's nuclear and missile programs. Iran has rejected both resolutions as illegal, saying it won't give up its right to enrich uranium and produce nuclear fuel.

State television, meanwhile, reported that Iran has inaugurated a new air base near its eastern border with Afghanistan to protect against a possible strike by enemy forces operating in the neighboring country.

The new base is part of a broader military buildup by Tehran, which is concerned about the U.S. military's presence in neighboring Iraq and Afghanistan at a time of heightened tension between the two nations.

"Inauguration of this air base was aimed at responding to a possible strike swiftly and strongly if a strike or attack is launched against the country," the head of Iran's air force, General Ahmad Mighani, told state television Tuesday.