Bahrain on Thursday warned Iran to stop interfering in its internal affairs while affirming its support for a union between the six nations of the Gulf Cooperation Council.

Foreign Minister Sheikh Khaled bin Ahmed Al-Khalifa made the remarks a day after Iran called on its people to protest on Friday against the union that Gulf officials say will start with Bahrain and Saudi Arabia.

The United States could let Iran partially enrich uranium in return for strict measures to curb its ability to build a nuclear bomb, the Los Angeles Times reported Friday.

In what would be a major concession, Washington could agree to allow Tehran to enrich uranium up to five percent purity if the Islamic Republic agrees to unrestricted inspections of its nuclear sites and other conditions, the newspaper said, citing U.S. officials.

Iraqi Prime Minister Nouri al-Maliki arrived in Tehran on Sunday for two days of meetings with Iranian leaders and senior officials on various bilateral issues, Iran's IRNA state news agency reported.

The visit notably comes ahead of an important May 23 meeting to be hosted in Baghdad between Iran and the P5+1 group of world powers on Tehran's disputed nuclear program.

Iran has called on the West to look to lifting its sanctions if it wants to quickly resolve the showdown over Tehran's disputed nuclear activities, a prospect swiftly ruled out by Washington.

Foreign Minister Ali Akbar Salehi outlined his country's message in an interview with the news agency ISNA on Monday, following milestone talks at the weekend in Istanbul between Iran and world powers.

Foreign Minister Ali Akbar Salehi said on Monday that Iran will not give up its right to enrich uranium, but hinted the level of enrichment is open to discussion.

The international community is concerned, particularly Iran's nemesis Israel, about Tehran's growing capacity to enrich uranium, which can be used for peaceful purposes but, when purified further, for a nuclear weapon.

Talks between Iran and six world powers in Istanbul on Tehran's nuclear program, the first in 15 months, began Saturday in a "positive atmosphere," a European Union spokesman said.

"There is a positive atmosphere. ... There is a desire for substantive progress," Michael Mann, spokesman for EU foreign policy chief Catherine Ashton, told reporters.

Iran on Monday urged "honesty" at crucial talks with world powers due to be held this week in order to defuse a tense international showdown over its disputed nuclear activities.

"We hope the P5+1 will come to the negotiating table with honesty, and we also will make an honest effort so that both sides reach a win-win conclusion," Foreign Minister Ali Akbar Salehi told the Iranian parliament's website.

Israeli Defense Minister Ehud Barak on Sunday warned the six-power group negotiating with Iran to set stringent limits on its nuclear enrichment at forthcoming talks.

"If the P5+1 will set a much lower threshold, like just stop reaching 20 percent it means that basically the Iranians at a very cheap cost bought their way into continuing their military programs, slightly slower but without sanctions," Barak said in English in an interview aired on Sunday by CNN.

Thai prosecutors have referred a case against five Iranian bomb suspects to court for a possible trial, a senior police officer said Sunday.

Deputy national police chief Pansiri Prapawat told reporters that the case was submitted to Bangkok's Criminal Court last week.

Iran on Sunday backtracked on reports that five Iranian "engineers" abducted in Syria had been freed -- the second time in months it retracted news of their liberation.

Kazem Sajjadi, a foreign ministry official in charge of Iranians abroad, told state television that five Iranian pilgrims who had been kidnapped separately had been released, but that the five engineers remained captives.