Taoiseach Mr. Varadkar faced criticism for being "mean" and "disgusting to statesmen" after his mockery by responding to a Twitter user who sent a message with his mouth open, citing the loans that the United Kingdom had awarded to Ireland during the financial crisis.
The user of social networks, which has 28 followers, published: "What the hell can you do, a country that borrowed millions from the United Kingdom, just to survive, offer anyone, you're laughing, another Irish joke."
In response, Mr Varadkar seemed to mock the UK after Brexit, as he suggested that Ireland is ready to come to the rescue of the UK if it suffers a financial collapse after leaving the EU.
He published on Twitter: "We have returned everything we borrowed from the IMF.
"Ireland has no budget deficit now and we have a rainy day fund.
"I'm glad to do the same for the UK and help them financially in the future if they need it for any reason …"
Furious Twitter users quickly attacked the Irish leader for "teasing neighbors and friends" and urged him to stay away from the "keyboard battles".
One said, "I'm not sure that kind of mockery with friends and neighbors is good for Leo's diplomacy, like the chosen Irish Taoiseach, you may want to overcome the keyboard battles."
Another published: "The Taoiseach joking about lending the money of the United Kingdom while still in the trap of the United Kingdom makes him look foolish, childish and very little statesman".
One added: "Varadkar's comment is not what is needed, the president of the Republic of Ireland should be showing some leadership, not trying to score insignificant points."
Varadkar's excavation comes after he warned last week that there was a "real risk" of a return to violence in Ireland if a hard border was restored between Northern Ireland and Ireland after Brexit.
Speaking today, the Irish leader said the UK government will not want to move away from its commitments to the support agreement.
The Taoiseach said he has "all the confidence" that the British government will fulfill its commitment to the Irish border.
Mr. Varadkar said: "From our point of view, what Ireland is looking for is what we have always been looking for from the first day and what we have committed to us and the UK Government in principle and in writing on several occasions. now. .
"That is to say, we have a backing that gives us the assurance that there will not be a hard border on the island of Ireland no matter what, that support is legally operable and that it applies unless there is a new agreement.
"That is something the UK Government has committed to in principle, in writing, and I have full confidence that the UK Government will honor that commitment."
"Britain is an important country, a serious country, a great country with a great history, I do not think they want to get away from their commitment."
It comes after Prime Minister Theresa May told parliamentarians that she could not accept the original EU support plan, as it would mean imposing controls on goods traded between Northern Ireland and the rest of the United Kingdom, creating "a customs border in the Irish Sea".
She is now demanding a limited time solution to the problem of the Irish border.
While ready to explore "all possible options" to break the deadlock, she said that a "critical" first step should be a legally binding agreement in a joint temporary customs territory of the United Kingdom and the EU to avoid the need for a single Northern Ireland barrier.