DUBLIN >> Holding up his family history as an example, President Joe Biden on Thursday told lawmakers in a packed parliament building that the story of Irish immigrants setting sail for the U.S. is at the very heart of “what binds Ireland and America together.”

“Like so many countries around the world, though perhaps more than most, the United States was shaped by Ireland,” Biden said in address to a joint sitting of the Oireachtas in Leinster House. “And the values we share remain to this day the core of the historic partnership between our people and our governments.”

Biden stressed the importance of economic ties, a united front on the war in Ukraine and a shared urgency to manage climate change. Biden addressed parliament as part of his four-day trip to Ireland and Northern Ireland, where he also met with political leaders and took a whirlwind tour of his ancestral homeland.

Ceann Comhairle Seán Ó Fearghaíl, speaker of the Dail, parliament’s lower chamber, told Biden that Ireland has benefitted “immensely” from American investment, and noted that it goes both ways — Ireland is the ninth-largest source of foreign direct investment in the U.S.

“Long may this bilateral investment continue,” Ó Fearghaíl said to cheers. He welcomed Biden “home” as he introduced him. Biden was the fourth U.S. president to address the Irish parliament, after John F. Kennedy, Ronald Reagan and Bill Clinton.

For Biden, Ireland has been the backdrop for discussion about his favorite themes, like dignity, “possibilities,” democracy — and poetry. He addressed parliament on what would have been the 84th birthday of his favorite poet, Seamus Heaney. Ó Fearghaíl gave Biden a signed copy of Heaney’s poems, and Heaney’s widow was present for the speech, watching as Biden quoted “The Cure at Troy.”

The president spoke with poetic flourishes about how the two nations could “dream together over horizons we can’t see.” He talked about visiting County Louth this week, gazing out at the sea from the stone balcony of Carlingford Castle, which would have been the last Irish landmark that Owen Finnegan, Biden’s maternal great-great-grandfather, saw before sailing for New York in 1849.

“These stories are at the very heart of what binds Ireland and America together,” he said. “They speak to a history, defined by our dreams.”

The 80-year-old Biden also reflected on his age, something he rarely does publicly. He said was “at the end of my career, not the beginning.” He told the Irish lawmakers “you can see how old I am,” saying he comes to the job more experienced than any other president in American history.

“It doesn’t make me better or worse, but it gives me few excuses,” he said. Biden is expected to run for reelection, and would be 82 were he to start a second term.

Earlier Thursday, Biden met with Taoiseach Leo Varadkar, Ireland’s prime minister, praising the nation for its humanitarian work welcoming Ukrainian refugees. Ireland has hosted nearly 80,000 refugees from Ukraine following Russia’s invasion, and it has been staunchly supportive of U.S.-led efforts on the war. Biden said he was impressed by Ireland’s commitment.

“I think our values are the same,” Biden told Varadkar. “And I think our concerns are the same. So I’m really looking forward to continuing to work with you.”

Biden also met with with Irish President Michael D. Higgins at his grand Dublin residence. The two octogenarian leaders clasped hands and laughed as they walked inside along a red carpet. Biden signed the guest book with a writerly missive for Ireland’s poet-president: “As the Irish saying goes, your feet will bring you where your heart is. It’s an honor to return.”

Biden helped shovel dirt around a freshly planted Irish oak, not far from one planted years earlier by then-President Barack Obama. He also rang the Peace Bell, unveiled in 2008 to mark the 10th anniversary of the Good Friday Agreement, which ended decades of violence in Northern Ireland. Biden clanged the bell four times, including one “for all my Irish ancestors, and a fourth one for peace.”

Then he thanked Higgins, who turns 82 next week.

“I’m feeling great, and I’m learning a lot,” Biden said at Higgins’ estate. “I know it sounds silly, but there’s many Irish-Americans, like my relatives, who’ve never come back here.”

Varadkar and Biden also exchanged toasts at a dinner banquet at Dublin Castle.

Biden opened the trip earlier this week in Belfast, Northern Ireland, where he marked the 25th anniversary of the Good Friday Agreement that ended years of sectarian violence. The U.S.-brokered deal brought peace to a region of the United Kingdom where “the Troubles” left some 3,600 people dead in bombings and other attacks.

Addressing parliament Thursday, Biden said the United Kingdom “should be working closer” with Ireland to support Northern Ireland. His reminder of the importance of maintaining a quarter century of peace in Northern Ireland was likely to irk some British Conservatives and Northern Ireland unionists, who are suspicious of U.S. interference.

Biden arrived in the Republic of Ireland on Wednesday, a day after he landed in Northern Ireland. Crowds lined five-deep and waited for eight hours to catch a glimpse of Biden in County Louth, where his mother’s family is from. In the town of Carlingford, the Democratic president toured a castle, gazing out over the sea where his ancestors sailed toward America.

From inside a packed old pub with a sticky wooden floor, Biden acknowledged that his ancestors emigrated to the United States to escape famine, but he added, “When you’re here, you wonder why anyone would ever want to leave.”

The president was elated by the dive into his Irish heritage, which he often cites as a driving force in his public and private life. According to the Irish Family History Centre, Biden “is among the most ‘Irish’ of all U.S. Presidents.” Ten of his 16 great-great-grandparents were from the Emerald Isle.