Iranian Foreign Minister Mohammad Javad Zarif
Iranian Foreign Minister Mohammad Javad ZarifReuters

Iran's foreign minister, Mohammad Javad Zarif, moved Tuesday to dismiss speculation that his country's nuclear deal with major powers could hit difficulties, saying he had "no concern or worry" about its implementation, according to AFP.

Zarif's remarks came during a news conference with visiting EU foreign policy chief Federica Mogherini, as they seek to ensure that the agreement swiftly takes effect.

Mogherini also met President Hassan Rouhani Tuesday, AFP reported.

"The same way that efforts were taken for reaching agreement, (we) should concentrate on its accurate and complete implementation so that our nations and all the world enjoy its benefits," Rouhani was quoted as having said.

The past week has seen hardline elements, including the commander of the powerful Revolutionary Guards force and some MPs, raise concerns about the agreement's terms.

Under the deal, Iran must take measures at its nuclear facilities to satisfy UN monitors of their peaceful nature.

In return, the world powers must finalize the mechanism for lifting UN and Western sanctions.

Zarif gave a timeline of "60 to 70 days" for the deal to be settled, following talks with Mogherini about measures that are needed.

"Iran will continue to cooperate with the IAEA," he said, referring to the UN nuclear watchdog - the International Atomic Energy Agency.

"I hope the EU and United States will continue to implement their commitments," added Zarif.

Asked about accusations in some conservative Iranian media that the agreement breaks supreme leader Ayatollah Ali Khamenei's "red lines", Zarif moved to allay such claims.

"Iran has stuck to its obligations and Iran is going to do the same when it comes to implementing the deal," he said, acknowledging that "some people in Iran have some doubts about some countries, particularly the United States, to implement seriously and precisely".

Since the deal was struck, Khamenei has attacked the United States and its Western allies several times.

In his first public statement after the deal was reached, the Supreme Leader warned that some of the parties on the other side were not trustworthy.

"Reaching a deal is a significant step, but the text of the deal should be carefully scrutinized and the legal procedures should be taken so when the deal is ratified the other side cannot breach it," he wrote in a letter to Iran’s President Hassan Rouhani.

"Some of the members of the P5+1 are not trustworthy," he said, referring to the six world powers, though he did not mention any of them by name.

"I ask our dear nation to stay calm and united so we can preserve our national interests in a serene and sensible environment," Khamenei wrote.

He later publicly declared that the Islamic Republic will not respect the United States any more for the deal and its attitude towards the Americans would not change.

"We have repeatedly said we don't negotiate with the U.S. on regional or international affairs; not even on bilateral issues," Khamenei declared. "There are some exceptions like the nuclear program that we negotiated with the Americans to serve our interests."

"We will never stop supporting our friends in the region and the people of Palestine, Yemen, Syria, Iraq, Bahrain and Lebanon," he continued, referring to the Iranian terror axis in the Middle East. "Even after this deal our policy towards the arrogant U.S. will not change."

The speech was punctuated by cries of "Death to America" and "Death to Israel."