Keir Starmer has promised European leaders he will reset Britain’s ties with their countries as the prime minister uses his first international summit on domestic soil to draw a line under years of fractious relations with continental Europe.

The prime minister used his opening speech at the European Political Community summit at Blenheim Palace on Thursday to reassure the leaders of more than 40 other countries that he wanted to renew “trust and friendship” with them.

British ministers are hoping to use the summit as a chance to explore future talks on migration and trade, with Starmer hoping to eventually secure new deals with the EU on returning asylum seekers and trading defence and agricultural products.

Starmer told the summit: “We want to work with all of you to reset relationships, rediscover our common interest and renew the bonds of trust and friendship that brighten the fabric of European life.”

He added: “We will strengthen our existing relationships and we will build new ones.

“This includes resetting our relationship with the EU because I believe that the UK and the EU, working together as sovereign partners, are a powerful force for good across our continent.”

He contrasted his approach with that of his predecessor, Rishi Sunak, who upset some European allies with his plans to deport asylum seekers to Rwanda and by threatening to leave the European convention on human rights if the scheme was blocked in Strasbourg.

Starmer said: “We are resetting our approach. This government will not commit taxpayer money to gimmicks. We will approach this issue with humanity and with a profound respect for international law, and that’s why we scrapped the unworkable Rwanda scheme on day one.”

And in the most full-throated defence of the ECHR from a British prime minister in years, Starmer – who once wrote a textbook on European human rights law – said: “I myself first read about these principles of the convention and international law in a law library in Leeds, well, 40 years ago now. That inspired me in everything I have done since then and I still draw strength from it, and value from it, every day.”

European leaders arriving at the summit said they were largely optimistic about the chances of renegotiating parts of Britain’s relations with the EU.

Josep Borrell, the EU’s chief diplomat, said: “We welcome the new tone of the British government and we look forward to engaging with it. We are ready to reinforce our foreign and security policy cooperation.”

Charles Michel, the president of the European Council, said: “On the field of migration, we can see how we can deepen the ties, how we can cooperate more together.”

Simon Harris, the Irish taoiseach, said the Labour government was a “gamechanger” for the EU.

“You have a British government that wants to actively talk about a closer relationship with Europe, the importance of multi-relevant-lateralism, staying within the ECHR, working closely with Ireland, talking about language around co-guarantor of our peace process. It’s a very different landscape.”

While British and European leaders have spoken warmly about the possibility of a renegotiation, formal talks remain some way off. David Lammy, the foreign secretary, said on Thursday morning the UK was “nowhere near” negotiating agreements with the EU.

Lammy told BBC Breakfast: “Of course, we’re entering into discussions but we’re nowhere near a negotiation on the trade agreement – that paper-thin trade agreement that Boris Johnson struck – the veterinary deal that we’ve said that we want to get, the mutual qualifications that we want to work on, and the UK-EU security pact that we’re proposing to Europe that will enable us to discuss a whole range of issues across the European family.”