Sir Keir Starmer promised a “pragmatic, sensible” approach to the UK-EU relationship in order to “make Brexit work” as he held talks in Brussels.
The Prime Minister met European Commission chief Ursula von der Leyen, saying he was determined to put the relationship with Brussels on a “stable, positive footing”.
Sir Keir is pushing for a better trading relationship and greater co-operation on defence and security measures as part of a drive to “reset” UK-EU ties.
He added that “in dangerous times we have a duty to work together to preserve stability and security”, referring to the crisis in the Middle East and the war in Ukraine.
Sir Keir said: “We are determined to put this relationship back on a stable, positive footing that I think we all want to see.”
Ms von der Leyen said the various arrangements put in place since the Brexit vote, including the Trade and Co-operation Agreement (TCA) needed to be fully implemented.
She said: “We have a set of solid agreements in place. We should explore the scope for more co-operation, while we focus on the full and faithful implementation of the Withdrawal Agreement, the Windsor Framework and the TCA.”
He was also holding separate meetings with European Council chief Charles Michel and the European Parliament’s Roberta Metsola, during his first visit to Brussels as Prime Minister.
No concrete announcements are expected from the first formal meetings between Sir Keir and the Brussels chiefs.
The European Commission said the meeting with Ms von der Leyen would be “the beginning of a conversation”.
The Prime Minister is under pressure to agree to Brussels’ calls for a deal on youth mobility, to allow young EU citizens greater freedom to come to the UK to study and work and vice versa, something he has so far resisted.
The Prime Minister’s red lines for the reset rule out a return to the single market, the customs union or freedom of movement.
But pro-EU campaigners have pushed for him to give ground on a youth mobility scheme.
Sir Nick Harvey, chief executive of European Movement UK, said: “Dismissing the idea of reciprocal youth mobility simply means letting down British young people, who face all sorts of economic difficulties and have seen their horizons curtailed by Brexit.”
