* U.N. nuclear watchdog reported failed Tehran talks
* Iranian envoy hopes for more meetings (Adds IAEA report due later on Friday, quote, detail)
By Fredrik Dahl
VIENNA, Feb 24 (Reuters) - Iran wants more talks with the U.N. nuclear watchdog, its ambassador to the body said, despite what one Western envoy called "very long and fruitless" negotiations this week on addressing suspicions about Tehran's atomic activities.
The relatively upbeat comments by Iran's ambassador to the International Atomic Energy Agency (IAEA) were in stark contrast to a terse statement issued by the U.N. agency on Wednesday after the two days of discussions in Tehran.
The Vienna-based agency is later on Friday expected to issue its latest quarterly report on Iran's nuclear programme, giving details on this week's meetings in Tehran and the overall status of the Islamic state's uranium enrichment drive, diplomats say.
The report to member states could form the basis for any diplomatic action against Iran at a March meeting of the IAEA's 35-nation board, which has the power to adopt resolutions and can report a country to the U.N. Security Council.
Iran's envoy to the IAEA stressed the need for dialogue, warning against any "provocation" that could jeopardise this.
"Our position is that we are going to continue the talks for cooperation with the agency and we hope that this process will be successfully going on," ambassador Ali Asghar Soltanieh said.
"We need a quiet environment, a calm environment to continue our professional work with the agency," he told Reuters late on Thursday.
The IAEA said no further meetings with Iran were planned, signalling frustration at the lack of progress in two rounds of talks this year.
The setback has increased fears of a spiral towards conflict between Iran and the West, and sent oil prices higher.
Western diplomats suspect Iran is merely seeking "talks about talks" in an attempt to ease outside pressure on the Islamic state while it presses ahead with nuclear work which the United States and its allies believe has military aims.
Iran says nuclear weapons claims are baseless and its programme is aimed at electricity generation and medical needs.
"We try to be cooperative," said Soltanieh. "We are dealing with the questions and we are trying to remove ambiguities."
The IAEA said Iranian officials refused to grant it access to a military site crucial for its investigations and that there was no agreement on a way forward to clarify concerns that the Islamic Republic may be developing nuclear arms capability.
Western diplomats said Iran had continued to stonewall the senior IAEA team during the talks, in which the agency sought answers to intelligence pointing to nuclear weapons research and development.
"Essentially they had two very long and fruitless meetings," one Western envoy in Vienna said.
The Iranian side "systematically just claimed they have no clandestine programme and therefore any questions raised (about possible military dimensions to Iran's nuclear programme) were either incorrect or invalid", the diplomat added.
An IAEA report in November suggested Iran had pursued military nuclear technology. This helped to precipitate the latest sanctions by the European Union and United States.
One finding was information that Iran had built a large containment chamber at the Parchin military site near Tehran to conduct high-explosives tests. The U.N. agency said there were "strong indicators of possible weapon development".
Asked why Iran had not allowed the U.N. inspectors to visit Parchin, Soltanieh said: "For any visit and access there should be some sort of modality and agreement.
"It was assumed that after we agreed on the modality then access would be given. Since the modality was not concluded due to time constraints ... this was not possible." (Editing by Janet Lawrence)