The Taoiseach says Britain's red lines are the only barrier to a close relationship between the EU and UK after Brexit.
Leo Varadkar made the comments in a 'Future of Europe' lecture in Brussels last night.
He also said "real and solid" progress on the border issue must be made by June before negotiations can move on.
The Taoiseach has called on the UK to soften its position on the single market and customs union.
"From Ireland's perspective we want the future relationship between the EU and the UK to be as close and comprehensible and ambitious as possible.