Taoiseach Micheál Martin has raised concerns about the Covid-19 situation in Northern Ireland with British Prime Minister Boris Johnson.
He also spoke to Stormont's First and Deputy First Ministers Arlene Foster and Michelle O'Neill about the issue on Monday evening.
The Northern Ireland Executive, meanwhile, is meeting to discuss measures to tackle the spiralling rate of Covid-19 infections.
It is expected to announce tougher penalties for breaches of regulations. A hike in coronavirus fines and extending the places where face coverings are mandatory are being considered by Stormont ministers.