The United States has quit negotiations on a voluntary pact to deal with migration because the global approach to the issue was "simply not compatible with US sovereignty", said US ambassador to the United Nations Nikki Haley.
In a statement released late on Saturday, the US mission noted that President Donald Trump made the decision.
"No country has done more than the United States and our generosity will continue," said Ms Haley, whose parents are immigrants from India. "But our decisions on immigration policies must always be made by Americans and Americans alone."
“We will decide how best to control our borders and who will be allowed to enter our country,” she said.
Trump campaigned last year on a promise to deport large numbers of immigrants and build a wall along the Mexico-US border to tackle illegal immigration and crime in the United States. Since he took office in January, he has also moved to ban US entry by people from select Muslim countries.
Declaration
With a record 21.3 million refugees globally, the 193-member UN General Assembly adopted a political declaration in September last year in which it also agreed to spend two years negotiating the pact on safe, orderly and regular migration.
Former US president Barack Obama’s administration backed the resolution, known as the New York Declaration, which also asked UN high commissioner for refugees Zeid Ra’ad al-Hussein to propose a global compact on refugees for adoption in 2018.
“The global approach in the New York declaration is simply not compatible with US sovereignty,” said Ms Haley.
Regretted
UN secretary-general Antonio Guterres regretted the US decision, said his spokesman but he expressed hope the United States might re-engage in the talks.
"The positive story of migration is clear: it needs to be better told. Equally, the challenges it throws up need to be tackled with more determination and greater international co-ordination," said UN spokesman Farhan Haq.
Three days of preparatory talks begin in Mexico on Monday ahead of the start of formal negotiations in February over the non-binding pact.
Ms Haley's predecessor Samantha Power mocked the US move.
“How to further insult your Mexican neighbour, turn your back on humanity’s most desperate and make America irrelevant on a hugely destabilising global crisis in one easy step,” she said.
Former UN deputy secretary-general Jan Eliasson said: "On migration, national solutions logically do not exist . . . Going it alone is a lose-lose proposition."