By Louis Charbonneau
(Reuters) - U.S. Secretary of State John Kerry on Tuesday suggested that Washington would not insist that Iran answer unresolved questions about its past nuclear activities because the United States already knows exactly what Tehran has done.
U.S. officials have previously said Iran must answer a set of queries the U.N. International Atomic Energy Agency (IAEA) has about past Iranian activities that may have been related to atomic weapons research and that some sanctions relief under a possible nuclear deal would depend on resolving those questions.
So far, the IAEA has been unable to resolve all of its questions about so-called possible military dimensions of past Iranian nuclear work. Tehran says the agency's evidence about past weapons-related activities is fabricated and insists its nuclear program is peaceful.
Speaking to reporters via teleconference, Kerry suggested Washington was prepared to be flexible on this issue.
"We're not fixated on Iran specifically accounting for what they did at one point in time or another," Kerry said. "We know what they did. We have no doubt. We have absolute knowledge with respect to the certain military activities they were engaged in."
"What we're concerned about is going forward," Kerry said. "It's critical to us to know that going forward, those activities have been stopped, and that we can account for that in a legitimate way."
The United States, Britain, France, Germany, Russia and China have a self-imposed June 30 deadline to finish a long term nuclear deal with Iran under which it would curb sensitive nuclear activities for at least a decade in exchange for sanctions relief.
Officials close to the talks say they will likely run into early July.
An interim deal between Iran and the six powers from April said Iran would need to address the IAEA's concerns under any final agreement.
Over the weekend, Israeli Prime Minister Benjamin Netanyahu accused the six powers of stepping up concessions to Tehran as the deadline for a deal approaches.
Separately, U.S. Ambassador to the United Nations Samantha Power rejected on Tuesday suggestions by a U.N. sanctions monitoring panel that Washington may be keeping silent about Iranian sanctions violations to avoid disrupting the nuclear talks.
The panel said in April it has received no new confirmed reports of Iranian violations despite numerous media reports of Iranian weapons shipments abroad in violation of a U.N. embargo.
"Absolutely not," Power told a congressional hearing. "There's no pulling of our punches, even during these negotiations."
(Reporting by Louis Charbonneau; Editing by Grant McCool)