The visit by Sheikh Tahnoon bin Zayed Al Nahyan comes as the Emirates and Saudi Arabia are both negotiating with Iran amid efforts in Vienna to save Tehran's tattered nuclear deal with world powers.

Sheikh Tahnoon met first with Ali Shamkhani, the head of Iran's Supreme National Security Council. The two men smiled and shook hands in front of journalists before their meeting.

Iranian state television quoted Shamkhani as saying that 'warm and friendly' relations between the countries remain a priority and that they shouldn't be affected by other nations _ likely a reference to the United States and Israel.

Sheikh Tahnoon later met with President Ebrahim Raisi, a hard-line protege of Supreme Leader Ayatollah Ali Khamenei. A statement from the presidency quoted Raisi as welcoming 'improved ties with the Emirates', including on economic issues.

'There should be no barrier in relation of the two Muslim nations of Iran and the Emirates', Raisi said. 'It should not be affected by foreigners' dictation'.

The Iranian presidency quoted Sheikh Tahnoon as inviting Raisi for a state visit to the UAE. A report by the UAE's state-run WAM news agency did not mention the invitation, but said the two 'discussed prospects of consolidating bilateral ties and explored an array of issues of common interest'.

Monday marked a series of political visits in the region against the backdrop of the Vienna talks in Europe. Syria's Foreign Minister Faisal Mekdad also visited Tehran, and Saudi Crown Prince Mohammed bin Salman was to visit Oman on a regional tour. Meanwhile, Turkish President Recep Tayyip Erdogan was to travel to Qatar, which Prince Mohammed also planned to visit soon.

Ali Bagheri Kani, an Iranian deputy foreign minister leading the Vienna talks, also recently traveled to the UAE for talks.