European leaders, including Prime Minister Edi Rama, will meet in the UK next week.
In addition to EU member states, non-eu countries including Norway, Iceland, Georgia, Kosovo, Serbia, Albania and Turkey are invited, according to The Guardian.
Turkish President Recep Tayyip Erdogan, who did not attend previous summits, has not yet confirmed the attendance.
Thursday's conference is the fourth meeting of the European Political Community, initiated after the Russian invasion of Ukraine in February 2022, the idea of French President Emmanuel Macron.
It is seen as a "very significant" opportunity for britain's new prime minister, Keir Starmer, to not only host up to 50 European leaders, but restore trust in the UK and show the world that the country is back on the international stage after years of reputational damage caused by Brexit.
The EPC was created to facilitate the strengthening of ties between EU and non-EU leaders with previous conferences held in Spain, Moldova and the Czech Republic.
As host, Starmer will speak at the opening plenary session, which will be held in one of the halls at Blenheim Palace, the birthplace of Winston Churchill. He is expected to underline the UK's commitment to Ukraine and Zelensky, and to the reset of the country's post-Brexit relationship with the EU.
The prime minister has already pledged to establish closer ties with the EU and the new minister for European relations, Nick Thomas-Symonds, traveled to Brussels on Monday for a presentation meeting with former Brexit negotiator Maroš Šefčovič.
Ahead of the meeting, Starmer said: "Europe is facing one of the greatest challenges of our time.
"Russia's barbaric war continues to resonate across our continent as vile smuggling gangs traffic innocent people on dangerous journeys that too often end in tragedy.
"I said I would change the way the UK engages with our European partners, working collaboratively to advance progress on these generational challenges, and that work begins at the Meeting of the European Political Community on Thursday."
Irish chief Simon Harris has pledged to support the UK at European level and has instructed his ministers to increase contact with London counterparts.
Starmer will have a series of bilateral talks, he will meet Harris the night before at Checkers and is expected to have a separate meeting with Macron on Thursday, in addition to taking assumptions from EU leaders about a new security and defence pact with the UK after Brexit.
Ukraine will dominate the plenary discussion with the leaders, who will then be invited to join three defence and democracy-focused working groups, which will include sessions on the disinformation crisis, energy and migration.
Security will be strict with airspace restrictions over the Oxfordshire palace between July 14 and 18. Police drones and the police air service will enforce the restricted airspace, according to Thames Valley police.
Zelensky will make his first visit to Ireland on Saturday morning, when he will land at Shannon Airport, Co Clare, for a meeting with Irish chief, Simon Harris .