President Barack Obama has told Iran the United States would accept Tehran having a civilian nuclear program if the Islamic state can prove it is not seeking atomic weapons, the Washington Post said Friday.

Obama sent such a message to Tehran via Turkish Prime Minister Recep Tayyip Erdogan, who delivered it to Iran's Supreme leader Ali Khamenei last week, said the newspaper's foreign affairs columnist David Ignatius.

"President Obama has signaled Iran that the United States would accept an Iranian civilian nuclear program if Supreme leader Ali Khamenei can back up his recent public claim that his nation 'will never pursue nuclear weapons'," said Ignatius.

"A few days before traveling to Iran, Erdogan had held a two-hour meeting with Obama in Seoul, in which they discussed what Erdogan would tell the ayatollah about the nuclear issue and Syria," he wrote.

The United States said Thursday that it still expected Iran to hold talks with six world powers on the Islamic republic's disputed nuclear program to go ahead next week, despite a dispute on the venue being Istanbul or Baghdad.

According to Ignatius, Obama asked Erdogan to tell Khamenei "that the Iranians should realize that time is running out for a peaceful settlement and that Tehran should take advantage of the current window for negotiations."

However, "Obama didn't specify whether Iran would be allowed to enrich uranium domestically as part of civilian program the United States would endorse. That delicate issue evidently would be left for the negotiations."

Turkey has told Iran it remains ready to host the talks between Iran and the P5+1 group, Iran's Al-Alam television station reported Friday, but the Islamic republic has said it wanted the meeting held in Baghdad or China instead.

Iran last held talks with the six powers -- Britain, China, France, Germany, Russia and the United States -- in January 2011 with no results.

Ignatius added that "the challenge for negotiators is whether it's possible to turn Khamenei's public rhetoric into a serious and verifiable commitment not to build a bomb."