Micheál Martin and his British counterpart Boris Johnson discussed post-Brexit trade and the Ballymurphy massacre during a meeting at Chequers, No 10 said.
A Downing Street spokesperson said: "The leaders reflected on the Coroner's report into the Ballymurphy massacre published this week. They agreed it was profoundly sad that the families of victims had to wait so long for the truth.
"The Prime Minister restated the UK Government's commitment to finding a way forward in Northern Ireland that delivers for victims, aids truth recovery and helps communities in the future.
"They agreed on the importance of working together to uphold the Belfast/Good Friday Agreement and to maintain smooth trade between Great Britain, Northern Ireland and the Republic of Ireland.
Relatives of those killed at Ballymurphy have criticised a letter of apology Boris Johnson sent to them on Thursday for failing to describe the shootings at Ballymurphy in 1971 as a "massacre".
The Downing Street statement about Friday's meeting with Micheál Martin did use that term in relation to the killings.
Following the meeting, Micheál Martin tweeted: "Wide-ranging & constructive discussions with @BorisJohnson today on British-Irish relations, including the long struggle for justice by the Ballymurphy families.
"We also reaffirmed both governments' commitment to the Good Friday Agreement and its institutions."
An Irish Government statement said: "The Taoiseach and Prime Minister had constructive engagement across a number of issues, including the Covid-19 response, support for peace and stability in Northern Ireland, and the broader British-Irish relationship.
"The two leaders, in particular, discussed the long journey of the Ballymurphy families for justice to vindicate the innocence of their loved ones.
"They also discussed British-Irish relations, and both are ambitious for the development of the next phase of the bilateral relationship framed around a number of areas of common interest.
"The Taoiseach and Prime Minister had a good exchange on the response to the Covid-19 pandemic and the value of working together. They agreed to remain in close touch over the coming weeks."