* Obama warns next negotiating round will be challenging
* Interim deal on Iran nuclear activity takes effect Jan. 20
* EU's Ashton to travel to Tehran in coming weeks
* U.S. concerned about reports of Iran-Russia swap
(Adds U.S. comments on reports of Iran-Russia oil-for-goods
swap, Obama on sanctions, paragraphs 8-12, 22-24)
By Justyna Pawlak
BRUSSELS, Jan 13 Big powers and Iran are likely
to start talks on a final settlement to the long dispute over
its nuclear ambitions in February, shortly after a six-month
deal curbing its atomic activity takes effect, a diplomatic
source said on Monday.
If successful, the next round of negotiations could head off
the risk of lingering mistrust spiralling out of control into a
wider Middle East war over the Islamic republic's nuclear
Led by European Union foreign policy chief Catherine Ashton,
the talks will face the challenge of defining a permissible
scope of Iranian nuclear activity that would lay to rest Western
concerns that it could yield an atomic weapon.
In return, Iran - which denies having any intention to
"weaponise" the enrichment of uranium for nuclear energy - wants
governments in the United States and Europe to end painful
The source said the first meeting in the new phase of
diplomacy between Iran and six powers - the United States,
Russia, China, France, Britain and Germany - would include
Ashton and Iranian Foreign Minister Mohammad Javad Zarif.
"It won't happen in January, because of the Chinese New
Year, but it is very, very, very likely in February," the
diplomat said, speaking on condition of anonymity.
Senior diplomats from the seven countries and the EU will
discuss an agenda ahead of the meeting. Ashton herself announced
plans on Monday to go to Tehran in the coming weeks in
preparation for more talks.
U.S. President Barack Obama said on the weekend he had "no
illusions" about how hard it would be to secure a comprehensive
agreement with Iran.
His administration voiced concern on Monday about recent
reports that Iran and Russia are negotiating an oil-for-goods
swap worth $1.5 billion a month, a deal the White House said
could potentially trigger U.S. sanctions.
Russian and Iranian sources close to the barter negotiations
have said final details are being discussed for a deal under
which Russia would buy up to 500,000 barrels a day of Iranian
oil in exchange for Russian equipment and goods.
"We are concerned about these reports and Secretary (of
State John) Kerry directly expressed this concern with Foreign
Minister (Sergei) Lavrov today," Caitlin Hayden, spokeswoman for
the White House National Security Council, told Reuters.
"If the reports are true, such a deal would raise serious
concerns as it would be inconsistent with the terms of the P5+1
agreement with Iran and could potentially trigger U.S.
sanctions," Hayden said.
Iran says its atomic energy programme is aimed purely at
generating electricity and producing isotopes for medical care.
But past Iranian attempts to hide sensitive nuclear activity
from U.N. non-proliferation inspectors raised global concerns.
Reached on Nov. 24, the interim six-month agreement freezes
Iran's most sensitive atom work - higher-level enrichment - in
return for an estimated $7 billion in relief from sanctions.
Iran and the six powers said at the weekend the deal would
go into effect on Jan. 20, pending verification by the
International Atomic Energy Agency that Tehran is meeting its
end of the bargain.
The preliminary accord appeared to arrest a drift towards
regional war during which the United States and Israel have both
refused to rule out military action against Iranian nuclear
sites if the matter cannot be resolved diplomatically.
'LONG AND DIFFICULT ROAD'
Underscoring the challenge of the new talks, Zarif said on
Monday the interim agreement was "the beginning of a long and
"There is a very serious confidence deficit vis-a-vis the
West in Iran. Our people believe that our peaceful nuclear
programme has been dealt with in a totally unfounded way," Zarif
told a news conference during a visit to Lebanon.
Later in the week, he is due to meet Russian President
Vladimir Putin in Moscow, Russian officials said on Monday.
Russia's Foreign Ministry issued a statement welcoming the
weekend decision to launch the interim accord on Jan. 20.
"We hope that a successful implementation of the primary
phase will create the necessary conditions for working out
agreements going further that will result in a final and
comprehensive settlement in regard to Iran's nuclear programme,"
the ministry said.
In Washington, Obama urged Congress to resist the temptation
to approve new economic sanctions against Iran, saying, "Now is
the time for us to allow the diplomats and technical experts to
do their work."
Raising the issue in comments to reporters, Obama said that
if Tehran abides by the agreement, "then I have no doubt that it
can open up extraordinary opportunities for Iran and their
But if they refuse, he said, then "we are in position to
reverse any interim agreement and put in place additional
pressure to make sure that Iran does not obtain a nuclear
French Foreign Minister Laurent Fabius said an exact date
for the resumption of the next talks had yet to be set.
(Additional reporting by Parisa Hafezi in Ankara, Gabriela
Baczynska in Moscow, Babak Dehghanpisheh in Beirut, John Irish
in Paris, Sylvia Westall in Kuwait, Roberta Rampton, Steve
Holland and Mark Felsenthal in Washington; editing by Luke
Baker, Mark Trevelyan, Mark Heinrich, Peter Cooney and Cynthia