European Commission chief Jean-Claude Juncker says the risk of Britain leaving the European Union without a divorce deal remains "very real."

Speaking at the European Parliament in Strasbourg, France, Juncker, who met with British Prime Minister Boris Johnson on Monday, said a no-deal Brexit "might be the choice of the U.K., but it will never be ours."

The European Parliament is debating Brexit on Wednesday and is set to adopt a resolution laying out its concerns.

European Commission President Jean-Claude Juncker delivers his speech Wednesday, Sept. 18, 2019 in Strasbourg, eastern France, as members of the European Parliament discuss the current state of play of the UK's withdrawal from the EU. (AP PhotoJean-Francois Badias)

European Commission President Jean-Claude Juncker delivers his speech Wednesday, Sept. 18, 2019 in Strasbourg, eastern France, as members of the European Parliament discuss the current state of play of the UK's withdrawal from the EU. (AP PhotoJean-Francois Badias)

The main sticking point over a Brexit deal is the Irish border backstop, which would require Britain to retain some EU trade rules.

Juncker said "I have no sentimental attachment to the backstop" but that he remains attached to the purpose it serves. He says "I asked the British prime minister to specify the alternative arrangements that he could envisage."

European Commission President Jean-Claude Juncker delivers his speech Wednesday, Sept. 18, 2019 in Strasbourg, eastern France, as members of the European Parliament discuss the current state of play of the UK's withdrawal from the EU. (AP PhotoJean-Francois Badias)

European Commission President Jean-Claude Juncker delivers his speech Wednesday, Sept. 18, 2019 in Strasbourg, eastern France, as members of the European Parliament discuss the current state of play of the UK's withdrawal from the EU. (AP PhotoJean-Francois Badias)

European Commission President Jean-Claude Juncker delivers his speech Wednesday, Sept. 18, 2019 in Strasbourg, eastern France. Members of the European Parliament discuss the current state of play of the UK's withdrawal from the EU. (AP PhotoJean-Francois Badias)

European Commission President Jean-Claude Juncker delivers his speech Wednesday, Sept. 18, 2019 in Strasbourg, eastern France. Members of the European Parliament discuss the current state of play of the UK's withdrawal from the EU. (AP PhotoJean-Francois Badias)

Brexit Party leader Nigel Farage, left, shakes hands to European Commission President Jean-Claude Juncker while European Union chief Brexit negotiator Michel Barnier, right, looks on Wednesday, Sept. 18, 2019 in Strasbourg. Members of the European Parliament discuss the current state of play of the UK's withdrawal from the EU. (AP PhotoJean-Francois Badias)

Brexit Party leader Nigel Farage, left, shakes hands to European Commission President Jean-Claude Juncker while European Union chief Brexit negotiator Michel Barnier, right, looks on Wednesday, Sept. 18, 2019 in Strasbourg. Members of the European Parliament discuss the current state of play of the UK's withdrawal from the EU. (AP PhotoJean-Francois Badias)