UNITED NATIONS — US President Joe Biden told Britain’s new prime minister, Liz Truss, in their first official talks Wednesday that they are both “committed” to maintaining the Good Friday Agreement that brought peace to Northern Ireland.

“We are both committed to protecting the gains” of the pact, Biden told Truss at their meeting on the sidelines of the UN General Assembly in New York.

Truss, attending her first UN session as British leader, said she was “looking forward to discussing the Belfast Good Friday Agreement, and how we make sure that’s upheld into the future.”

Truss has expressed hope she can negotiate a resolution to a dispute between Britain and the European Union over post-Brexit trade in Northern Ireland.

The dispute centers on where to establish a customs border now that Britain is cut from the European single market — either between mainland Britain and Northern Ireland or between Northern Ireland and EU member Republic of Ireland.

Pro-UK unionist parties object to having their home region isolated from the mainland.

However, putting a hard border instead between the British portion of Ireland and the independent Republic of Ireland would go against a key provision of the 1998 Good Friday peace deal, which stipulated removing border infrastructure as part of a bargain that ended 30 years of violent opposition to London’s rule.

The White House said after the bilateral meeting that the two leaders also pledged to maintain close US-British cooperation on helping Ukraine to resist Russian invasion.

“The leaders committed to continuing their governments’ close coordination on global challenges, including support for Ukraine as it defends itself against Russian aggression, addressing challenges posed by China, and securing sustainable and affordable energy supplies,” it said in a statement.

Biden also reiterated his condolences over the death of Queen Elizabeth II, whose funeral he attended in London on Monday, the White House said.