Minister for Foreign Affairs Charlie Flanagan has said the plight of undocumented Irish in the US is "not just a St Patrick's Day issue".

Along with Taoiseach Enda Kenny, he will discuss immigration reform with the Speaker of the US House of Representatives John Boehner in Dublin on Thursday.

“This is not just a St Patrick’s Day issue. Every opportunity the Taoiseach has on his visits to the US, his engagement with President Obama and other leaders, this continues to be top of the agenda,” Mr Flanagan said.

Mr Flanagan said he himself had raised the issue of so-called illegals with US Vice President Joe Biden at a meeting in recent weeks.

He acknowledged that progress was unlikely until a court challenge to Mr Obama’s executive action was dealt with in the US.

However, he said he would stress the importance of advancing the “long-outstanding” issue with Mr Boehner “and his team of Republicans”.

He would tell them about the experiences of Irish people in the US, many from his own constituency, who were “in a position of limbo” because they had difficulty in securing a legal status.

“I believe it’s important that we continue to impress upon our American friends the need to have this matter advanced. I haven’t had the opportunity of speaking to Speaker Boehner before. I acknowledge that he is highly influential on the Hill.”

Mr Boehner, who is a staunch opponent of Mr Obama's political agenda, is a pivotal figure as his control of Republican votes in Congress can determine the fate of draft laws to overhaul immigration rules which have already passed the Senate.

Mr Flanagan said Mr Boehner's visit to Ireland was timely.

He also said they would discuss Ireland's role within the EU and the UK referendum on continued membership, as well as the conflict in Ukraine.