The Taoiseach says a protest outside his home in County Wicklow on Thursday was "out of bounds".
Images on social media show a number of people with banners outside Simon Harris's house in Greystones.
Placards reading 'South Dublin Says No' and 'Close the Borders' are seen in the images.
Speaking from Belfast, the Taoiseach said politicians' families and homes should not be subjected to such events.
"I don't want to say too much about this and I don't like describing those sort of things as protests," he said.
"I've a very clear view in relation to this - whether it's me, whether it's an opposition politician or whether it's quite frankly anybody.
"I always think people's families and people's homes should be out of bounds.
"It was bedtime for my kids last night when this situation arose - I don't think it's appropriate
"I don't really want to comment on it any further than that," he added.
A Garda investigation into the circumstances behind the protest has been launched.
Gardaí say they received a report of a gathering of people outside a home in Greystones after 7pm on Thursday.
They said those present gathered for less than 10 minutes before leaving the area.
Taoiseach Simon Harris is greeted by Northern Ireland First Minister Michelle O'Neill and Deputy First Minister Emma Little-Pengelly outside Stormont Castle, 3-5-24. Image: PA Images / AlamyMr Harris is in Northern Ireland for his first official trip there as Taoiseach.
He is meeting with the First Minister Michelle O'Neill and Deputy First Minister Emma Little-Pengelly.
Their meeting is discussing developments since the restoration of the Stormont Assembly in February and potential opportunities for "practical all-island cooperation".
Mr Harris is also meeting the speaker of the assembly Edwin Poots and is holding bilateral meetings with Alliance leader Naomi Long, UUP leader Doug Beattie and SDLP leader Colum Eastwood.
The Taoiseach will then attend the Duncairn Arts Centre before a visit to Queen's University Belfast.
