US President Joe Biden walks from the stage after addressing the crowd during a celebration event at St Muredach's Cathedral on April 14, 2023, in Ballina, Ireland.Getty

US President Joe Biden reiterated his desire to run in the 2024 presidential election at the end of his four-day visit to Ireland on Friday night. 

Speaking to reporters on the tarmac at Knock Airport before departing for the US, Biden said he would be making an official announcement about his candidacy relatively soon. 

"I told you my plan is to run again," Biden told reporters.

"I've already made that calculus. We'll announce it relatively soon. But the trip here just reinforced my sense of optimism about what can be done." 

Asked if he had gotten what he wanted from his trip to Ireland, Biden said there was more work to be done in Northern Ireland but said he wanted to inspire optimism in the region. 

"There’s a lot at stake. A lot at stake. And I think the combination of Ireland – the whole island – Great Britain, Northern Ireland, the United States can change the way things occur on the continent," Biden said. 

"Look, think about it. Think about how much the economy is growing. Think about what’s happening here. Think about the technology. Think about the cybersecurity capabilities." 

At the beginning of his visit, Biden promised to boost US investment in Northern Ireland by up to $6 billion if power-sharing was restored in the region. 

Biden's visits to his ancestral homelands in Carlingford, County Louth, and Ballina, County Mayo, are expected to provide a boost to tourism in both regions.

Fáilte Ireland CEO Paul Kelly revealed that the tourism board is already capitalizing on the global media attention on both towns. 

Biden was also asked if he was sad to leave Ireland and said he was "anxious" to get home. 

"No, I’m anxious to get home," Biden said. "I love Ireland, I love the people, and I love working with the taoiseach. But, you know, home is where my heart is. And it’s real."

Biden said he learned some "interesting" facts about his family lineage during his trip to Ireland, including that he has distant relatives on his father's side living in Galway. 

Taoiseach Leo Varadkar said it was a really good visit and thanked Biden for spending so much time in Ireland.