Chile has pulled out of hosting two major international summits, including a UN climate change conference, as anti-government protests continue.
President Sebastián Piñera said the decision had caused him “pain” but his government needed “to prioritise re-establishing public order”.
The COP25 climate summit was scheduled for 2 to 13 December, while the Apec trade forum was next month.
The UN said it was now looking at alternative venues.
World leaders were to gather at this year’s Conference of the Parties (COP) to discuss the implementation of the Paris Accord – a landmark international climate agreement, first signed at COP21 in December 2015.
This is the first time a country has pulled out of hosting the conference at such short notice.
Chile’s decision comes amid global climate protests, including a week of strikes led by environmental activist Greta Thunberg last month.
And as the news was announced, a US-based organisation also separately revealed that tens of millions more people than previously thought were at risk of coastal flooding from climate-driven sea-level rise within the next century.
In a statement, the UN’s climate change executive secretary, Patricia Espinosa, said: “Earlier today, I was informed of the decision by the government of Chile not to host COP25 in view of the difficult situation that the country is undergoing. We are currently exploring alternative hosting options.”
It was also hoped the Asia Pacific Economic Co-operation (Apec) forum – due to be held in Santiago from 15 to 17 November – would help ease tensions between the US and China.
US officials said President Donald Trump had been planning to meet Chinese President Xi Jinping at Apec, to discuss a possible trade deal.
The two nations have been locked in an escalating trade war for some 18 months.
However, the White House confirmed that although a new location was yet to be found, the US still expected to sign an initial trade agreement with China next month.
“We look forward to finalising Phase One of the historic trade deal with China within the same time frame,” the White House said in a statement.
At least 20 people have been killed since the mass protests in Chile began.
While many protests were peaceful, there were also deadly incidents of arson and looting, as well as violent clashes between the security forces and protesters.
They have shown little sign of abating despite Mr Piñera announcing measures to ease Chileans’ discontent with high levels of inequality and other grievances.
More than 7,000 people have been arrested and the response by Mr Piñera’s government to the protests has come in for heavy criticism.
He declared a state of emergency and night-time curfews in many of Chile’s major cities, but the measures only seemed to further incense protesters.
A rally on Saturday is estimated to have drawn more than a million people to the streets of Santiago, in what organisers said was the largest demonstration since democracy was restored in Chile in 1990.