BELFAST, Northern Ireland (AP) - President Joe Biden is in Northern Ireland on Wednesday to help mark the 25th anniversary of the Good Friday Agreement, which brought peace to this part of the United Kingdom, as a new political crisis tests the strength of that peace.

On his first presidential visit to Northern Ireland, Biden was stressing that American investment can help fuel economic growth – especially if the fractious politicians in Belfast resolve a new political crisis that has rattled the Good Friday peace deal and put Northern Ireland’s government on pause.

In a speech at Ulster University’s new campus in downtown Belfast, Biden will focus on “Northern Ireland’s vast economic potential,” said Amanda Sloat, the Democratic president’s top adviser on European affairs.

She said Biden will talk about “how the last 25 years were focused on peace but the next 25 years should be marked by growth and economic prosperity.”

U.S. involvement was key to negotiating the Good Friday accord, which largely ended decades of sectarian violence that killed 3,600 people. While that peace has endured, Northern Ireland is currently without a functioning government.

Stormont, the seat of its assembly, has been suspended since the Democratic Unionist Party, which formed half of a power-sharing government, walked out a year ago over a post-Brexit trade dispute.

Biden’s schedule on Wednesday began over tea with U.K. Prime Minister Rishi Sunak. Asked what he would tell the leaders of Northern Ireland’s five main political parties when he meets with them later in the day, Biden responded, “I’m going to listen.”

Sloat said that while Biden wants to see the Stormont government back up and running, he won’t try to strongarm Northern Ireland’s politicians back to the table.

“The purpose of the president’s visit today is to mark the Good Friday Agreement, to continue to reaffirm the support of the United States for peace and prosperity,” she said. “The president’s message ... is the United States’ strong support for that, the belief that the people of Northern Ireland deserve to have a democratically elected power sharing representative governance.”

The political crisis stems, in part, from Brexit. Britain’s departure from the European Union left Northern Ireland poised uneasily between the rest of the U.K. and EU member Ireland and put the peace agreement under increased strain.

After much wrangling, Britain and the EU struck a deal in February to address the tensions over trade, an agreement welcomed by the U.S., which had urged London and Brussels to end their post-Brexit feud. The Democratic Unionist Party, though, says the Windsor Framework doesn’t go far enough and has refused to return to government.

As he set off for Belfast on Tuesday, Biden said a priority of his trip to Northern Ireland was to “keep the peace.”

While U.K. officials hope the president’s presence can help nudge the unionists back into government, but Biden faces mistrust from some unionists because of his Irish American heritage.