UPDATE 5-Biden underscores need to maintain Northern Ireland peace, will not weigh in on UK-EU row

Adds Harris meeting with Northern Ireland officials

By Andrea Shalal and Trevor Hunnicutt

WASHINGTON, March 17 (Reuters) - U.S. President Joe Biden said on Wednesday it was "critically important" to maintain Northern Ireland's peace process, but a senior aide said the U.S. government would not take sides in a UK-EU rift over movement of goods to the British-ruled province.

As Biden held a virtual meeting with Irish Prime Minister Micheál Martin on St. Patrick's Day, he underscored his support for the 1998 Good Friday peace agreement that ended decades of bloodshed in Northern Ireland.

In a joint statement, the two called for a good faith implementation of the peace accord and other international agreements designed to address the unique circumstances on the island of Ireland.

"We strongly support that, and think it's critically important to be maintained," Biden said. "The political and economic stability of Northern Ireland is very much in the interest of all our people."

Biden and Martin also pledged to expand ties between the two close allies, including on issues such as climate change, combating the coronavirus pandemic, and cancer research.

Both men expressed the hope to meet in person soon.

Biden, who often speaks with pride of his Irish roots, said the White House would be illuminated in green later Wednesday to "celebrate the deep, deep affection" Americans had for Ireland. White House fountains also ran green, continuing a tradition dating to former President Barack Obama, whom Biden served as vice president.

"The key objective is of course to deepen our relationship," Martin told MSNBC earlier. "In President Biden, we have the most Irish-American president since John F. Kennedy, and his election was greeted with great affection and warmth in Ireland."

The Irish leader thanked Biden for his "unwavering support" of the Good Friday agreement, adding, "It has meant a lot. And it has mattered."

"With a new trading relationship now in place between the European Union and the United Kingdom, and a protocol that protects peace and avoids a hard border on this island, I want to move forward with a positive relationship with the United Kingdom," Martin said. "That means standing by what has been agreed and working together to make a success of it."

There have been disputes over the implementation of agreements put in place as the UK exited the EU, including the Northern Ireland protocol, which governs movement of goods into the province. According to the withdrawal agreement, Northern Ireland remains in the EU single market for goods, and so requires checks on goods arriving there from other parts of the UK. nL8N2LD4H4

The Biden administration viewed the rift as a trade issue to be resolved between Britain and the EU, and would not take sides, a senior administration official said before the meeting.

The dispute has rekindled tensions in Ireland more than two decades after the peace accord largely ended three decades of violence between mostly Protestant unionists who want Northern Ireland to stay in the UK and mostly Roman Catholic nationalists seeking to unite the Irish Republic and Northern Ireland.

This month, Northern Irish loyalist paramilitary groups said they were temporarily withdrawing support for the 1998 peace agreement due to concerns over the Brexit deal.

The groups said they believed Britain, Ireland and the EU had breached their commitments to the peace deal. nL5N2L21OD

Provisions in the EU-UK trade and cooperation agreements, and the Northern Ireland protocol, should protect the gains of the peace agreement, the U.S. official said, adding the "hope that both sides are able to return to the table and discuss the implementation of the agreement."

Martin has said Ireland, an EU member, is counting on U.S. support to help maintain political stability in Northern Ireland. nL1N2LC0BJ

Biden stopped by a separate virtual meeting that Vice President Kamala Harris had scheduled with Northern Ireland First Minister Arlene Foster and deputy First Minister Michelle O'Neill, the White House said in a statement.

The U.S. officials expressed their strong support for the peace agreement and the Northern Ireland protocol, and encouraged the leaders to "continue working together toward a forward-looking Northern Ireland with a prosperous economy that reflects the identities and aspirations of all traditions."

The virtual meeting with Martin was the first bilateral event with Ireland hosted by Biden, who attended a St. Patrick's Day Mass at his church in Delaware before returning to Washington. Biden is expected to make a trip to Ireland as soon as this summer.

(Reporting by Andrea Shalal and Trevor Hunnicutt; Additional reporting by Steve Holland in Washington and Conor Humphries in Dublin; Editing by Peter Cooney, Rosalba O'Brien and David Gregorio)

((trevor.hunnicutt@tr.com; +1 646 223 7914; twitter.com/trhunnicutt; Reuters Messaging: trevor.hunnicutt.thomsonreuters.com@reuters.net))