Taoiseach Leo Varadkar said he wants to renew the close bond with the UK ahead of talks with Theresa May in Downing Street.
In his first official overseas visit since being elected Taoiseach last week, Mr Varadkar travels to London where Northern Ireland and Brexit will top the agenda.
"I am looking forward to travelling to Downing Street today to meet the British Prime Minister, Theresa May," he said.
"I want to renew the close bond and strong relations that exist between Ireland and the United Kingdom.
"Among other things, we will discuss Northern Ireland and the need to re-establish devolved Government, and Brexit, focusing on how we can avoid any adverse impact on the rights and freedoms of our citizens, on trade and the economy."
Northern Ireland's political parties are reopening talks aimed at restoring devolution to the region.
They have until a June 29 deadline to agree a way forward after Sinn Fein collapsed the Stormont Executive earlier this year amid deepening mistrust and worsening relations with the Democratic Unionist Party.
The DUP's deal to prop up the Tories at Westminster is also likely to be discussed at Downing Street.
Last week, Mr Varadkar warned Ms May about getting too close to the DUP, as both governments have roles as co-guarantors of the Good Friday Agreement, which secured peace in the region after decades of conflict.
The Taoiseach said he would be emphasising this to the Prime Minister.
The pair shared a phone call on Thursday.
Ms May said she was steadfastly committed to the Good Friday Agreement and wanted to see a "close and special partnership" with the Republic of Ireland post-Brexit.