The European Parliament has called for the UK to trigger Article 50 "as soon as possible".
MEPs earlier today passed a motion calling for the UK to commence formal negotiations by activating Article 50.
It came after a debate in which European Commission President Jean-Claude Juncker reasserted his view that the UK should make haste on triggering the provision of the Lisbon treaty.
Speaking during an Extraordinary European Parliament meeting, Juncker said the UK should "clarify its position" on Brexit as soon as possible, while adding that the UK and European parliament would remain friends.
"We need to clarify the situation as quickly as possible. But I'm still sad because I'm not a robot, a grey bureaucrat or technocrat," Mr Juncker said, alluding to how he feels he has been portrayed in the UK.
"I'm a European and I have a right to say I regret the result of the British vote."
On Friday Juncker, European Council President Donald Tusk, European Parliament President Martin Schulz, and Dutch PM Mark Rutte, said: "We now expect the United Kingdom government to give effect to this decision of the British people as soon as possible, however painful that process may be. Any delay would unnecessarily prolong uncertainty."
However German Chancellor Angela Merkel has said she is in no rush, but has added if it was left too long contagion could ensue. French President Francois Hollande and Italian Prime Minister Matteo Renzi backed her up.
In further developments, Merkel today, speaking in the Bundestag, said that access to EU markets "comes with obligations".
She told the German parliament that countries hoping for access to the EU's free market must respect the EU's basic values.
So, any state which leaves cannot expect to keep the privileges of membership without keeping to their obligations too, Reuters reported.
Merkel added that she wants to keep close relations with the UK.
Juncker and Merkel agreed that formal or informal talks cannot get started until Article 50 has been triggered.
Some members of the Leave camp in the UK have suggested that there is no rush to enable the provision.
However, influential MEP Guy Verhofstadt told the European Parliament that he could not understand why "Brexiteers" did not now want to trigger it as soon as possible.