By David Young, Press Association
Michel Barnier will hold talks with Leo Varadkar in Ireland later ahead of this week's crunch summit in Brussels.
The EU's chief Brexit negotiator will discuss the latest developments with the Taoiseach in Dublin on Monday afternoon.
Mr Barnier will also meet deputy premier and foreign affairs minister Simon Coveney and finance minister Paschal Donohue.
The engagements at Government Buildings in the city come prior to the meeting of the EU27 on Wednesday when European leaders will discuss Theresa May's request for a further Brexit extension.
At the weekend, Mr Varadkar said his own preference was for a longer extension than the June 30 date proposed by the UK.
"What we want to avoid is an extension that just allows for more indecision and more uncertainty," he added.
Mr Varadkar also said the prospect of one of the EU27 saying no to any form of extension at the European Council meeting was "extremely unlikely".
The Taoiseach said any country that vetoed a further Brexit extension would not be forgiven by other member states.
Mr Barnier's visit is the latest evidence of intensifying diplomatic exchanges between the Dublin government and key EU figures in the Brexit process.
Last week, Mr Varadkar held bilateral meetings with French President Emmanuel Macron in Paris and German Chancellor Angela Merkel in Dublin.