The European Commission chief has called for the UK to "clarify its position" to avoid uncertainty across the bloc. UKIP's leader implored the bloc to offer Britain a "sensible tariff-free deal."
The European Parliament on Tuesday urged the UK to immediately trigger the formal process of leaving the EU after the "Leave" camp gained a tight victory in an in-or-out referendum last week.
The "will expressed by the people needs to be entirely and fully respected, starting with an immediate activation of Article 50," said a resolution adopted by European lawmakers at an unprecedented emergency session, with 395 in favor and 200 against.
At the session, European Commission President Jean-Claude Juncker urged the UK to clarify its future on short order. "I want the UK to clarify its position. Not today, not tomorrow at 9 am, but soon. We cannot allow ourselves to remain in a prolonged period of uncertainty," Juncker said.
Juncker said he banned his policy commissioners from participating in informal negotiations with the UK after members of the "Leave" campaign said they hoped to negotiate a new deal before triggering the formal exit process.
"We will not start negotiating until intentions are made clear. No notification, no negotiation," Juncker said.
The UK must invoke the EU Constitution's Article 50 in order to begin the formal exiting process, which will last a maximum of two years after it is triggered.
'Best friends in the world'?
Meanwhile, "Leave" campaign leader and head of the United Kingdom Independent Party (UKIP) Nigel Farage called for Europe to take a "grown-up and sensible" approach and offer the UK a good deal following the so-called "Brexit" vote.
"If you were to decide to cut off your noses to spite faces and to reject any idea of a sensible trade deal, the consequences would be far worse for you than it would be for us," the UKIP leader said.
"Let's cut between us a sensible tariff-free deal and thereafter recognize that the UK will be your friend, that we will trade with you, we will cooperate with you, we will be your best friends in the world," Farage added.
The British leader of the right-wing party warned Brussels that other EU member states would follow suit.
"The UK will not be the last member state to leave the European Union," he said.
ls/kl (AFP, Reuters, AP)