The Financial Times has reported that the Taoiseach, Micheál Martin has told Joe Biden that the UK and EU must “stand by what has been agreed” on post-Brexit rules on trade between Great Britain and Northern Ireland. 

The two leaders were speaking by video link at the annual St Patrick’s Day bilateral meeting. The Taoiseach said London and Brussels must “move forward with a positive relationship” on the Northern Ireland protocol.

President Biden has been insistent that there must be no return to a hard border between the UK and the Irish Republic and that the 1998 Good Friday Agreement must be upheld. 
 
According to the Financial Times report, the Taoiseach said he wanted to thank the US president for his "unwavering support for the Good Friday Agreement" and that "it has meant a lot and it has mattered, including as we negotiated Brexit."

Source: www.businessworld.ie