Canadian government officials are on the ground in Tehran this week for the first time since the Harper government closed the Canadian Embassy there nearly five years ago.

The visit by Global Affairs officials comes just days ahead of a crucial presidential election in Iran, a country Canadian diplomats abandoned in 2012 partly due to security concerns.

A government source confirmed to CBC News the officials are in Tehran advocating for Canadians entangled in Iran's legal system, as well as for the improvement of Iran's overall human rights record.

The source familiar with the matter would not discuss the details of the consular cases involved, but said they were also raised in a call between the two countries' foreign ministers, held on Monday.

According to the source, the visit is also inevitably seen as a tangible sign that Canada is "committed to re-engaging" with Tehran, though no major breakthrough is yet expected in restoring the embassies that were closed when Ottawa quietly pulled its diplomats in 2012..

Restoring relations with Iran and reopening the respective embassies closed in 2012 in Ottawa and Tehran was a Liberal promise during the 2015 election.

The Maple Leaf on the windows is one of the few remaining hints that 57 Shahid Sarafraz St. in Tehran used to be the Canadian Embassy. (Nahlah Ayed/CBC)

Shortly after Justin Trudeau became prime minister, Canada lifted a number of sanctions on Iran, bringing Ottawa into line with several world powers that had agreed to do so under a deal with Iran to limit its nuclear capability.

The change, along with downgrading a warning against all travel to Iran, was partly aimed at encouraging Canadian business ties in a burgeoning market that had been sequestered under sanctions for more than a decade.

Thawing relations

The call between Global Affairs Minister Chrystia Freeland and Iran's Foreign Minister Javad Zarif, in addition to the arrival of the officials, is a further indication of the continuing thaw in relations between the two countries.

Zarif's first contact with a Canadian foreign minister was with Stéphane Dion on the sidelines of a UN meeting in New York in 2016 — a meeting largely motivated by the case of a Canadian professor detained in the notorious Evin prison. She was later released.

Canadian consular cases were again the focus of Monday's call, according to the government source. But the call also included a discussion on Iran's role in Syria.

Iran has played a significant role in supporting Syria's President, Bashar al-Assad.

Dialogue to advance human rights

A spokesperson for the minister said engagement with Iran remains a priority.

"We believe that open and frank dialogue, especially when we disagree, is the best way to effectively address security issues, hold Iran to account on human rights, and advance consular cases," said Alex Lawrence.

"We continue to oppose Iran's support for terrorist organizations, its threats toward Israel and its ballistic missile program."

Iranian Foreign Minister Mohammad Javad Zarif's conversation Monday with Canada's foreign minister included discussion on Iran's role in Syria. (Pavel Golovkin/Associated Press)

Iranian authorities have complained that Canada has been slow to implement re-engagement, and that Tehran is ready to restore relations, but Ottawa is dragging its feet. The Iranian Foreign Ministry says the ball is in Ottawa's court.

Iran is also keen on placing polling stations in Canada to allow Iranian expatriates to cast a ballot in the May 19 vote. That request is also likely to come up in Tehran in the coming days.

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​Due to privacy considerations, the government does not reveal how many Canadians are detained in Iran.

Web developer Saeed Malekpour, a Canadian resident, has been in a Tehran prison since he was arrested in 2008 on charges of insulting Islam.