Former US Vice President Al Gore suggested on Tuesday that the presidency of Donald Trump could end prematurely for “ethical reasons,” drawing laughter from a packed movie theatre at the European premiere of his latest film on climate change.

“We’re only six months into the experiment with Trump. Some experiments are ended early for ethical reasons,” Gore said, acknowledging the “provocative” nature of his comment.

Gore said he was convinced that US cities, states and business executives would meet US obligations under the 2015 Paris agreement to fight climate change, despite Trump's decision in June to withdraw from the global pact.

“We have a global agreement and the American people are part of this agreement in spite of Donald Trump,” he told hundreds of moviegoers at Berlin's Zoo Palast cinema after a showing of his new film, An Inconvenient Sequel: Truth to Power.

“We can win this... All we need is the political will,” he said, adding his hope that the United States would “soon once again” have a leader who was committed to halting global warming.

The film argues that fighting climate change is a just, moral battle, on a par with social movements such as the civil rights movement in the United States or the fight for gay rights.

Gore's first documentary, An Inconvenient Truth, is credited with bringing climate change into mainstream political discourse in the United States a decade ago.

Gore said he was confident the American and German people would remain united in their commitment to reversing the devastating effects of climate change already visible around the world on a daily basis.

He said he was “heartsick” about Trump's decision to pull out of the Paris deal, but said it could trigger an even stronger commitment by other nations to reduce greenhouse gases as an act of defiance.

He lauded Germany's leadership in moving toward alternative energy sources, and said global moves to shift to solar and wind power would drive economic growth and create many new jobs.

Donald Trump's international Presidential trips Show all 22 1 /22 Donald Trump's international Presidential trips Donald Trump's international Presidential trips French President Emmanuel Macron and US President Donald Trump AFP/Getty Images Donald Trump's international Presidential trips French President Emmanuel Macron and US President Donald Trump talk as they leave the Army Museum at Les Invalides in Paris AFP/Getty Images Donald Trump's international Presidential trips German Chancellor Angela Merkel and US President Donald Trump arrive for the group photo at the G7 Taormina summit on the island of Sicily in May 2017 Getty Images Donald Trump's international Presidential trips Mr Trump was pressed on the subject at the G7 summit in Italy Getty Donald Trump's international Presidential trips US President Donald Trump gives a speeech at the Warsaw Uprising Monument on Krasinski Square Getty Donald Trump's international Presidential trips US President Donald Trump and Britain's Prime Minister Theresa May during a ceremony at the NATO headquarters before the start of a summit in Brussels, Belgium Reuters Donald Trump's international Presidential trips Montenegro's Prime Minister Dusko Markovic is seen to the right of Donald Trump at a Nato summit in Brussels REUTERS Donald Trump's international Presidential trips Pope Francis meeting with US President Donald J. Trump EPA Donald Trump's international Presidential trips Pope Francis poses with US President Donald Trump and First Lady Melania Trump AFP/Getty Images Donald Trump's international Presidential trips US President Donald Trump arrives at Palazzo del Quirinale ahead of the meeting with Italian President Sergio Mattarella Ufficio Stampa Presidenza della via Getty Donald Trump's international Presidential trips US President Donald Trump is seen during a joint press conference with the Palestinian leader at the presidential palace in the West Bank city of Bethlehem AFP/Getty Images Donald Trump's international Presidential trips Palestinian president Mahmoud Abbas meets US President Donald Trump PPO via Getty Donald Trump's international Presidential trips Israeli Prime Minister Benjamin Netanyahu speaks with US President Donald Trump prior to the President's departure GPO via Getty Images Donald Trump's international Presidential trips US President Donald Trump and Israel's Prime Minister Benjamin Netanyahu shake hands after delivering a speech at the Israel Museum AFP/Getty Images Donald Trump's international Presidential trips US President Donald Trump and First Lady Melania Trump lay a wreath in the Hall of Remembrance as White House senior advisor Jared Kushner and Ivanka Trump watch on during a visit to the Yad Vashem Holocaust Memorial museum AFP/Getty Images Donald Trump's international Presidential trips US President Donald Trump visit to Yad Vashem Holocaust museum in Jerusalem accompanied by Prime Minister Benjamin Netanyahu GPO via Getty Images Donald Trump's international Presidential trips US President Donald Trump takes his seat before his speech to the Arab Islamic American Summit in Riyadh in Saudi Arabia Reuters Donald Trump's international Presidential trips Saudi Arabia's King Salman bin Abdulaziz al-Saud, US President Donald Trump and US First Lady Melania Trump look at a display of Saudi modern art at the Saudi Royal Court in Riyadh AFP/Getty Images Donald Trump's international Presidential trips US President Donald Trump and Saudi Arabia's King Salman bin Abdulaziz al-Saud take part in a signing ceremony at the Saudi Royal Court in Riyadh AFP/Getty Images Donald Trump's international Presidential trips King Salman presents Donald Trump with The Collar of Abdulaziz al-Saud Medal at the Royal Court Palace on 20 May AP Donald Trump's international Presidential trips US President Donald Trump is welcomed by Saudi King Salman bin Abdulaziz al-Saud upon arrival at King Khalid International Airport in Riyadh AFP/Getty Images Donald Trump's international Presidential trips U.S. President Donald Trump and first lady Melania Trump walk on the South Lawn prior to their first foreign trip Getty Images

The US State Department last week officially informed the United Nations that it would withdraw from the Paris deal, but left the door open to re-engaging if the terms improved for the United States.

But, in a diplomatic cable, US Secretary of State Rex Tillerson told US diplomats to sidestep questions from foreign governments on what it would take for the US government to re-engage in the Paris climate deal, Reuters reported earlier on Tuesday.