With its ancient ruins, glittering mosques and spectacular landscapes, Iran is home to some of the world's cultural treasures, but ever since the 1979 revolution, these have largely remained unseen by international tourists. In recent years, the country's most high-profile visitors have been nuclear inspectors from the International Atomic Energy Agency.

Now, however, the new administration of Hassan Rouhani is taking steps to open up Iran to foreigners in an effort to improve its international image after the gloomy years under Mahmoud Ahmadinejad – and to bring in much-needed foreign currency to an economy reeling from years of sanctions.

Mohammad-Ali Najafi, a vice-president and the head of the country's cultural heritage and tourism organisation, said Iran was overhauling its strict immigration rules to ease or abolish visa requirements for most foreign visitors.

"From the next two or three months, I predict that the number of foreign tourists who come to visit Iran as a tourist will greatly increase," said Najafi in a telephone interview from Tehran.

Najafi admitted some senior officials had been concerned at the prospect of allowing large numbers of tourists – especially westerners – in without prior security checks, but said that since Rouhani took office in August Iran's tourism body had eventually secured their support – and government approval.

The authorities will divide countries into three categories, Najafi said. Tourists from countries in the first group will not need a visa; visitors from the second group will be allowed in without a visa as long as they are part of an organised tour group; and visa procedures for the third group will be eased – meaning that many will be able to obtain a visa on arrival.

"Western countries will most probably be categorised in the second or third group," he said.

The semi-official Isna news agency has reported that except for 10 countries, including Britain, the US, Afghanistan and Pakistan, foreign tourists will be able to obtain visas upon arrival at the airport.

In September, Najafi was with Rouhani as the president travelled to New York for the UN general assembly. That visit marked a huge breakthrough in relations with the US, with the first direct talks between American and Iranian presidents since Iran's 1979 Islamic revolution, and renewed hopes that a solution can be found to the stalemate over Iran's nuclear programme.

The trip also opened up the possibility of a boost for the country's tourism industry. "When I was in America, I personally met with a number of tour operators, mainly those who are operated by Iranians in the US or non-Iranians who have had experience in dealing with Iran in the past," Najafi said.

After he was sworn in, Rouhani initially nominated Najafi as education minister but parliament accused him of previously having sided with the opposition Green movement and refused to sanction his appointment. Instead, Rouhani made him a vice-president, a cabinet position that does not require a parliamentary vote.

Iranians have also seen encouraging signs of the thaw at home: high-profile political prisoners have been released and the media face fewer restrictions. Najafi said the new political atmosphere had already encouraged more visitors.

"Over the past two months, many travel agencies have reported to us that the number of foreign tourists who have signed up to their Iran tours has increased a lot," he said. According to Najafi, four million foreign visitors came last year, mainly pilgrims from neighbouring countries such as Pakistan and Iraq who went to religious sites such as the Imam Reza shrine in Mashhad, a revered Shia site. "We don't have exact figures but we estimate that last year our tourism industry helped add some $2bn [£1.3bn] to our revenue," said Najafi. Now, Najafi said, the target was $10bn.

Goodwill ambassadors

Chinese tourists are a priority. "World figures show that China sends more tourists to visit other countries than anywhere else," Najafi said. "With help from our embassy in China, we have spoken to Chinese tourism officials and we have invited a number of them to come to Iran."

Najafi hoped foreign tourists would become "ambassadors for the goodwill of our country and our people" in the world. "We have a secure and safe country in our region … but we in Iran should take the first step in persuading westerners that they should have no fear in coming to Iran."

Unesco has so far declared16 world heritage sites in Iran, which was historically referred to as Persia in the west up until the 20th century.

In recent years, Iran's culture and heritage have fallen victim to the political dispute between Tehran and the west, which has dominated the global discourse on Iran. Brandon Stanton, an American citizen who travelled to Iran last year, attracted attention on returning home by posting an itinerary, along with pictures of Iran, on the Human of New York photo blog.

"Americans are especially loved," he wrote with astonishment. "This was noted in every travel account that I read, and I can confirm the fact. You will be smiled at, waved at, invited to meals, and asked to deliver personal messages to Jennifer Lopez. American music, movies, and media are thoroughly consumed by the people of Iran."

Amos Chapple, a photographer from New Zealand who has visited Iran on a number of times, said the Iran he saw was utterly different from the one represented in the west.

"Every traveller I met felt the same way: they had arrived expecting hostility and danger, but ended up amongst the most cosmopolitan and generous people in the Middle East," he said.

"Having visited three times it's just heartbreaking to see what damage the sanctions are doing to ordinary people who have nothing but goodwill towards America."

Zoe Holman, an Australian journalist who visited Iran for the first time in 2003, said: "Despite the divisions between 'the Muslim' and 'the west' being projected in geopolitics by the 'war on terror' and Iraq war, I was surprised, and humbled, to discover that none of these prejudices seemed to have trickled down to affect Iranian attitudes towards westerners.

"I was struck by the cosmopolitanism of urban Iranians, their education, open-mindedness and their humorous irreverence for the religious regime which governed them."

The Foreign Office currently advises against all but essential travel to most of Iran. Unlike tourists, journalists – especially those working for the foreign press – are usually unwelcome in the Islamic republic.