Theresa May arrived in Brussels on Friday morning following overnight talks on the issue of the Irish border.
The PM said there would be no hard border and the Good Friday Agreement would be upheld.
Speaking at an early morning press conference in Brussels, Mr Juncker said: “Today’s result is of course a compromise.”
Negotiations had been “difficult for both the UK and the EU”, he added.
Prime Minister Theresa May said getting to this point had “required give and take from both sides”.
The leader of Northern Ireland’s Democratic Unionist Party, Arlene Foster, said on Friday she was “pleased” to see changes which mean there is “no red line down the Irish Sea”.
Irish Foreign Minister Simon Coveney said the latest deal was a “very good outcome for everyone on the island of Ireland”.
On Monday, the DUP – whose support Prime Minister Theresa May needs to win key votes in Westminster – objected to draft plans drawn up by the UK and the EU.
With regard to EU citizens‘ rights, Mrs May said the agreement would guarantee the rights of three million EU citizens in the UK.
Their rights would “enshrined in UK law and enforced by British courts”.