Former Iranian president: Authorities must listen to popular demands
Authorities "should try to identify people's problems and hardships" instead of "humiliating" them, the reformist said in a statement published online.
He called for "an environment in which people could express their wishes and demands in all security without feeling intimidated" and without undermining the country's stability.
Protests began in the final days of 2017 in the north-eastern city of Mashhad, with anti-government rallies quickly spreading to other cities including Tehran, Khorramabad, Karaj and Sabzevar.
Thousands are thought to have taken part in the protests, making them the biggest show of public defiance since 2009, when Iranians - as part of the newly-formed Green Movement - took to the streets to denounce alleged rigged presidential elections by then-President Mahmoud Ahmedinejad.
The protests this time were initially centred around rising living costs, but quickly became focused against the regime in general with chants of "Death to the dictator".
According to authorities, twenty-five people were killed in the unrest, and 3700 were arrested.
Iranian officials across the political sphere have accused the country’s 'enemies' of fuelling the unrest. Iran's supreme leader blamed the country's "enemies" for the days of protests saying, "the enemy is always looking for an opportunity and any crevice to infiltrate and strike the Iranian nation."
The foreign ministry in Tehran also lashed out at US President Donald Trump after his latest Twitter attack on the Iranian authorities over the protests, insisting he should focus on "homeless and hungry people" in his own country.
At the start of the protests, Hassan Rouhani, the Iranian president, blamed the unrest on Iran's arch enemies, the United States and Israel.
"The enemy seizes any opportunity to harm the country", Khatami said, but "all institutions must recognise their share of blame" for the "shortcomings" highlighted by the recent protests, Khatami said.
Despite being barred from public appearances over his role in 2009 protests, Khatami remains one of the most popular figures in Iranian politics.
His endorsement was seen as crucial to President Hassan Rouhani's election in 2013 and 2017.
Rouhani, a moderate who secured a key 2015 nuclear deal with world powers, has pushed for greater civil liberties in the wake of the unrest.
On Tuesday, Rouhani called for "reinforcing democracy and listening to people's opinions" to counter any Western belief that Islam and democracy are incompatible.
The recent protests have exacerbated tensions between Rouhani and ultra-conservatives, who criticise the government's policy of outreach and accuse the president of neglecting the poorest members of Iran's population.