Six nations made the unprecedented move on Wednesday of asking the UN’s International Criminal Court to investigate Venezuela for possible crimes against humanity, even as President Nicolas Maduro made an unexpected trip to the world body’s headquarters to deliver a nearly hour-long speech declaring his nation “will never give in”.

Maduro’s speech at the General Assembly gathering of world leaders came hours after Argentina, Chile, Colombia, Peru, Paraguay and Canada formally asked the ICC to investigate Venezuela on a range of possible charges, from murder to torture and crimes against humanity.

“To remain indifferent or speculative in front of this reality could be perceived as being complicit with the regime. We are not going to be complicit,” said Paraguayan foreign minister Andres Rodriguez Pedotti.

The six countries hope the move puts new pressure on Maduro to end the violence and conflict that have sent more than 2 million people fleeing and made Venezuela’s inflation and homicide rates among the highest in the world.

Venezuelan officials have widely rejected international criticism, saying they’re driven by imperialist forces led by the US to justify launching an invasion.

The US wants to continue just giving orders to the world as though the world were its own property… Venezuela will never give in.

Venezuela's President Nicolas Maduro

And Maduro sounded a defiant tone on Wednesday night, complaining that Washington was attacking his country through sanctions and other means and strong-arming other countries into going along in a “fierce diplomatic offensive”. He said: “(The US) wants to continue just giving orders to the world as though the world were its own property… Venezuela will never give in.”

But at the same time, he said he was willing to talk with Trump.

Wednesday marked the first time that member countries have referred another country to the Netherlands-based UN court.

Canada was among nations referring Venezuela to the ICC, and Prime Minister Justin Trudeau seized the moment to defend the idea of global justice the court represents — the day after Trump attacked it in a stinging speech that challenged multilateral organisations.

Justin Trudeau speaks to reporters at the UN headquarters on Wednesday. AP

Its chief prosecutor, Fatou Bensouda, already has opened a preliminary investigation into allegations that Venezuelan government forces since April 2017 “frequently used excessive force to disperse and put down demonstrations”, and abused some opposition members in detention.

It is now up to the prosecutor — who didn’t immediately comment on the request — to decide what to do next. The six-country referral could broaden the scope of the ongoing preliminary probe to the more serious charges leveled at Venezuela on Wednesday and extend the time frame back to 2014.

Human Rights Watch was among those hailing the request, which was based on two reports: one by the UN High Commission for Human Rights that uncovered widespread extrajudicial executions and other violations, and another by an expert group designated by the Organization of American States that found reason to suspect 11 people, including Maduro, of crimes against humanity.

The request — announced on the sidelines of the UN General Assembly — also bolsters the idea that international bodies can hold corrupt or abusive leaders or governments responsible before their citizens.

Donald Trump at a news conference in New York during the United Nations General Assembly on Wednesday. AP

In an address to the General Assembly on Tuesday, Trump criticised what he called the “ideology of globalism' and said that as far as America is concerned, 'the ICC has no jurisdiction, no legitimacy, and no authority.'

The ICC was created in 2002 to prosecute war crimes, crimes against humanity and genocide in areas where perpetrators might not otherwise face justice. The court has 123 state parties that recognize its jurisdiction.

Trudeau steered clear of direct criticism of Trump and said Canada and the US share concern about the humanitarian crisis in Venezuela. But he also made clear Canada’s support for international co-operation to help developing nations “build a more peaceful, equal and stable world”. He said: “Because that’s what Canadians expect: That we stand up not just for ourselves but for everyone.”