* Iran won't ever slow down nuclear programme -Khamenei
* Next round of talks set for May 13 in Vienna
* Iran and 6 powers need to reach deal by July 20
* Tensions over Ukraine, Iran UN envoy don't hurt talks
(Adds Ashton, Zarif remarks)
By Louis Charbonneau and Fredrik Dahl
VIENNA, April 9 Iran will never slow down its
nuclear research programme,
the Islamic Republic's clerical supreme leader said on Wednesday
as negotiators from Tehran and six world powers struggled to
narrow "significant gaps" blocking the way to a long-term deal.
Ayatollah Ali Khamenei said Tehran's negotiating team should
not yield to issues "forced upon them".
"These negotiations should continue," he told nuclear
scientists in Tehran, the official IRNA news agency reported.
"But all should know that negotiations will not stop or slow
down any of Iran's activities in nuclear research and
Tehran denies suspicions that it is after nuclear weapons.
The negotiators from Iran and the so-called P5-plus-one -
the United States, Russia, China, Britain, France and Germany -
plan after their two days of talks in Vienna to start drafting
the agreement to meet a self-imposed July 20 deadline.
They will begin their next round of talks in the Austrian
capital on May 13, European Union foreign policy chief Catherine
Ashton, coordinating the talks for the powers, told reporters
while standing next to Iranian Foreign Minister Mohammad Zarif.
"A lot of intensive work will be required to overcome the
differences," she said. "We will now move to the next phase in
the negotiations in which we will aim to bridge the gaps in all
the key areas and work on the concrete elements of a possible
Zarif read out the same statement in Farsi.
The stakes are high. Western powers, along with Russia and
China, want to avert an escalation of tensions in the Middle
East in the form of a new war or a regional nuclear arms race.
Israel, believed to be only nuclear-armed nation in the Middle
East, has threatened to take military action against Iran if it
is not satisfied that the nuclear programme is curbed.
"The Iranians clearly have a sense of urgency to get a deal
done, as does the P5+1 (the six powers)," a senior diplomat
close to the talks said.
"We know that there are still some significant gaps that
remain and know this process will not be easy. But we're all
committed to getting it (an agreement) done by July 20," the
diplomat added, in an assessment echoed by other Western envoys.
The toughest areas to be tackled are Iran's future uranium
enrichment capacity, nuclear facilities that Western powers
believe have little or no civilian value, and future nuclear
research, as well as a sequence of steps to remove the
international sanctions that have crippled Iran's economy.
Despite Khamenei's pledge to the contrary, U.S. and European
officials say they will insist on limits to Iran's efforts to
develop more efficient enrichment technology, which would enable
Tehran to produce sensitive nuclear material at a faster pace.
Background tensions over Russia's involvement in Ukraine and
Western threats of further sanctions against Moscow and over the
U.S. denial of a visa for Iran's proposed new U.N. envoy in New
York have so far not harmed the nuclear talks, diplomats say.
A senior Iranian official said Tehran was seeking to protect
its "red lines" in what he said were "difficult" negotiations.
"Iran wants a deal in which its rights have been
considered," the official said. "The talks have entered a very
difficult stage. Making progress is difficult."
The third negotiating session in Vienna this year will
conclude on Wednesday with a meeting of senior foreign ministry
officials from the six powers chaired by Ashton and Zarif.
The six powers' goal is to extend as much as possible Iran's
so-called breakout" period - the time it would need to develop a
nuclear weapon. U.S. Secretary of State John Kerry said on
Tuesday the current Western assessment of Iran's capability in
this regard is two months.
Khamenei, who has the last say on Iran's affairs of state,
has repeatedly said that the oil-producing OPEC member's "red
lines" are that it will never give up enrichment or shut any
Among the most stubborn issues are Iran's centrifuge
research and development programme, the size of its uranium
stockpiles, the future of the Arak research reactor that could
eventually yield significant quantities of bomb-grade plutonium,
and the future of the Fordow underground enrichment plant, a
secret site until Western intelligence uncovered it in 2009.
Iran denies accusations that it is seeking a nuclear weapons
capability and wants an end to sanctions that have drastically
reduced its oil income and virtually barred it from the
international financial system. Tehran also wants to regain what
it regards as its rightful place as a leading regional power.
The current Vienna talks are building on a preliminary deal
that Iran and the six powers reached in Geneva last November.
That agreement provided Iran with limited sanctions relief in
exchange for a six-month suspension of some nuclear activities,
including higher-grade enrichment, that began on Jan. 20.
Yukiya Amano, director-general of the U.N. nuclear watchdog
in Vienna, told Reuters in Oslo that Iran is cooperating with
his inspectors seeking answers about detonators that could be
used to help set off an atomic explosive device, part of a wider
investigation into Iranian activities.
Western negotiators say that clarifying Iran's past nuclear
activities is essential if they are to be able to accurately
predict what Iran's future "break-out" capability will be.
(Additional reporting by Parisa Hafezi and Justyna Pawlak in
Vienna, Mehrdad Balali in Dubai; Editing by Mark Heinrich)