The Taoiseach is attending a Digital Summit in the Estonian capital of Tallinn examining cyber security into the future.
The summit is designed to focus attention on innovation, research and investment in Europe to help foster a digital revolution – however Brexit and the future direction of Europe are expected to dominate discussions.
Leo Varadkar last night attended a dinner with EU leaders including European Council President Donald Tusk - where they discussed issues including security and migration.
He is expected to use the summit to express his reservations over proposals to change rules on taxation in the digital sphere – specifically the idea of taxing companies where they generate revenue instead of where they are registered.
The summit will also see British Prime Minister Theresa May hold her first discussion with her German counterpart Angela Merkel since she delivered her landmark address on Brexit in Florence.
Dr Merkel was re-elected as German Chancellor last weekend, however gains for the far-right AfD party have weakened her political grip.
She now has many months of coalition building before she can form a government in Germany.
Separately the French President Emmanuel Macron delivered his vision for the future of Europe in a key speech on Tuesday.
Last night Mrs May told British troops stationed near EU border with Russia that the UK’s commitment to European security is unconditional.
She told the 800 UK soldiers stationed with NATO's Enhanced Forward Presence in Eastern Europe that it is in everyone's interests to confront the growing terror threat, illegal migration and increased Russian aggression together.
“While we are leaving the European Union, as I have said many times, we are not leaving Europe,” she said.
“So the United Kingdom is unconditionally committed to maintaining Europe’s security.”
Speaking ahead of her arrival in Tallinn, Mrs May said: "As we prepare for Brexit, I want to build a bold, new security partnership with the EU.”
"A partnership that reflects our shared history, promotes our common values, and maintains a secure and prosperous Europe," she said.
On Wednesday, the fourth round of negotiations concluded in Brussels with both sides claiming some progress.
"We have had a constructive week yes but we are not yet there in terms of achieving sufficient progress, more work is needed over the coming weeks and coming months," EU chief Brexit negotiator Michel Barnier said.
"The only way to reach sufficient progress is that all commitments undertaken at 28 [member countries] are honoured at 28," he said, referring to what he believes is Britain's responsibility to pay a financial settlement.
The UK Brexit Secretary, David Davis, said: "I believe that thanks to the constructive and determined manner with which both sides have conducted these negotiations we are making decisive steps forward.
"We've made important progress and capitalised on the momentum created by the Prime Minister's speech.
"But we must also acknowledge that a major question remains open between us - it relates to the enforcement of citizens' rights after we leave the European Union.
"The UK has been clear that, as a third country outside of the European Union, it would not be right for this role to be performed by the European Court of Justice."
The European Parliament's chief co-ordinator Guy Verhofstadt said he continues to believe that Brexit is a very negative project.”
“That it is in fact a waste of time and energy,” he said.
“The destruction of a strong political bond that made people on both sides of the channel richer, freer than ever before.”
EU negotiators have consistently stated that sufficient progress must be made on three key issues - the financial settlement, citizen's rights and the Irish border question - before talks on the future relationship can be held.
Additional reporting from IRN ...