BRUSSELS (AP) -- British Prime Minister Keir Starmer traveled to Brussels on Wednesday on a mission to try to improve ties with the European Union, which disintegrated as the country left the world's biggest trading bloc four years ago.

Starmer wanted to focus his talks on security, migration and trade. He was due to hold talks with the leaders of the bloc's main institutions: European Commission President Ursula von der Leyen, EU Council President Charles Michel and European Parliament President Roberta Metsola.

"The U.K. is undeniably stronger when it works in lockstep with its closest international partners. This has never been more important -- with war, conflict and insecurity all knocking on Europe's door," Starmer said in a statement released by his office ahead of the one-day trip.

Starmer said that he is "determined to put the Brexit years behind us and establish a more pragmatic and mature relationship with the European Union."

Better cooperation, he said, "will deliver the benefits the British people deserve -- securing our borders, keeping us safe and boosting economic growth."

The EU, for its part, wants to build bridges between young people on either side of the English Channel by introducing a scheme that would allow young EU and U.K. citizens to study, work and live for short periods in the U.K. and the EU respectively. Supporters of Brexit oppose it.

Since his center-left Labour Party's resounding election win on July 4, Starmer has sought a larger role for Britain on the global stage after years of soured relations with Europe over Brexit.

He has vowed to reduce some of the post-Brexit barriers for people and goods that have undermined ties between Britain and the bloc. Starmer insists though that he won't reverse Brexit, or rejoin the EU's single market and customs union.