Tehran, Feb 13 (IANS): Iran will not hold exclusive talks with the US on the sidelines of the upcoming nuclear negotiations with world powers in Kazakhstan, Iranian foreign ministry spokesman Ramin Mehmanparast has said.

Iran and the so-called P5 1 -- the US, Russia, China, France and Britain plus Germany -- will resume new round of talks in Almaty, Kazakhstan Feb 26.

Exclusive talks between Iran and the US was only possible when there are "signs of good will" from the Americans, Xinhua quoted Mehmanparast as saying.

He said that so far, there have been "no signs of this kind".

Top Iranian leaders have said the country was not interested in any talks with the US under "pressure".

Mehmanparast reiterated that any negotiations with Washington under pressure will yield no result.

Earlier this month, US Vice President Joe Biden said America was prepared to hold direct talks with Iran when the Iranian leadership is "serious".

Meanwhile, White House spokesman Jay Carney said "that pressure will continue (against Iran), and it will increase, as long as Tehran refuses to live up to its international obligations with regards to its nuclear programme".

The US has also expanded its sanctions on Tehran by tightening up economic measures and adding more names to a blacklist.