Iran said Saturday it had unintentionally shot down the Ukrainian airliner that crashed this week outside Tehran killing 176 people, calling it an "unforgivable mistake".The statement sparked some relief that at least the immediate cause of the disaster would not be concealed amid international calls for a full accounting and compensation for the victims.EXPLAINER: Iran, the US, Trump, ballistic missiles... and what comes nextIran has invited the United States, Ukraine, Canada and others to join the crash investigation.Herewith are some of the remarks made by top leaders in response to Iran's statement on its responsibility for the crash:Ukraine: 'Bring the guilty to court'Ukraine President Volodymyr Zelensky demanded that Iran punish those responsible, pay compensation and apologise."We expect Iran... to bring the guilty to the courts," the Ukrainian leader wrote on Facebook, calling for the "payment of compensation" and the return of remains."We hope the inquiry will be pursued without deliberate delay and without obstruction," Zelensky addedHe also urged "total access" to the full inquiry for 45 Ukrainian experts and in a tweet also sought an "official apology".Canada: 'Transparency, justice'Canadian Prime Minister Justin Trudeau, with the country mourning the loss of many of its nationals, said closure and accountability were needed after Iran's announcement.He demanded "transparency, and justice for the families and loved ones of the victims."This is a national tragedy, and all Canadians are mourning together," Trudeau's office said in a statement.Russia: 'Must learn lessons'Iran must "learn lessons" from the disaster, the chairman of the Russian parliament's foreign affairs committee said."If decryption of the black boxes and the work of the investigation do not prove that the Iranian army did this intentionally, and there are no logical reasons for this, the incident must be closed."Hoping that lessons will be learned and action taken by all parties," Konstantin Kosachev was quoted as saying by the Interfax news agency.France: 'End escalation'French Defence Minister Florence Parly said it was "important to seize this moment to give space to discussions and negotiations" on the Iran nuclear deal."The lessons that we should learn from the dramatic sequence of events that we have experienced... is that we must put an end to this escalation," Parly told France Inter radio.She reiterated the French position that everything must be done to salvage the landmark 2015 nuclear accord with Iran, which US President Donald Trump withdrew from in 2018.Germany: 'Draw the right consequences'German Foreign Minister Heiko Maas said "it was important that Iran brought clarity to this issue."Now Tehran needs to draw the right consequences in the continued appraisal of this dreadful catastrophe, and take measures to ensure that something like this cannot happen again," Mass told Funke media.Sweden: 'Complete and transparent' probePrime Minister Stefan Lofven said the "act should be condemned and Iran should assume all responsibility, including for the all persons affected."Iran said the plane was shot down in error. This declaration constitutes the basis for a complete and transparent investigation which should shed light on all the circumstances surrounding the incident," a statement said."We demand that Iran cooperates freely in the investigation and that the countries affected are allowed to participate using their national competencies and are fully informed about the investigation," he said.Foreign Minister Ann Linde tweeted that "the downing of a civilian plane even if it's not intentional must be condemned. We want Iran to fully cooperate in the investigation."