While Prince William, 42, traveled to New York for the Earthshot Prize Innovation Summit in 2023, he will not make the trip across the pond for this year’s event.

Prince William and Prince Harry were last together at the May 2023 coronation of their father, King Charles. However, the brothers didn’t appear to cross paths — while the Prince of Wales played a role in the ceremony as heir, the Duke of Sussex sat with other family members and left quickly after, heading back to his home in California where his son Prince Archie was marking his 4th birthday.

Since Prince Harry stepped back from his role as a working royal and relocated to California with Meghan Markle, the brothers have only been together a handful of times, including a July 2021 statue unveiling honoring their mother, Princess Diana, and the funeral events for their grandmother Queen Elizabeth in September 2022.

It’s been widely reported that the siblings’ rift began in 2016 when William expressed concerns about how quickly Harry’s romance with Meghan was moving. Harry went on to reveal details about the complex nature of his relationship with his older brother in his memoir, Spare.

Sources recently told PEOPLE that Prince Harry’s attempts to connect with Prince William are ignored.

The rift with Prince William is “very bad,” said a royal insider, but it’s not “irreparable.”

In addition to announcing the finalists for the $1.3 million Earthshot Prize awards, which aim to promote impactful approaches to the world’s most pressing environmental challenges, Prince William undertook additional outings during his two-day stay in New York in 2023, including a trip to Governors Island by boat to hear from the Billion Oyster Project’s efforts to revitalize local waterways and a visit to an FDNY firehouse. William even snuck in a jog at Central Park! “I decided to join the hordes of New Yorkers doing their morning routine,” he said.

The royal had hoped to head to New York for the Earthshot Prize Innovation Summit in 2022 but canceled the trip stateside following Queen Elizabeth’s death.

Prince Harry will be in New York City next month to “advance a number of his patronages and philanthropic initiatives,” his spokesperson said. He is expected to take part in engagements with charities and organizations with which he has a longstanding connection including African Parks, The HALO Trust and Travalyst. The Duke of Sussex will also lead an event with the Diana Award, a charity that continues his late mother Princess Diana’s work to empower young people.

The spokesperson added that Harry will also “be furthering the work of The Archewell Foundation, the nonprofit organization he co-founded with his wife Meghan, the Duchess of Sussex” during his trip to the East Coast.

Prince Harry, who visited Colombia with Meghan for a four-day tour earlier this month, most recently visited New York in October 2023 for the Archewell Foundation’s first in-person event. The summit gathered parents who experienced tragic loss connected to their child’s social media use.

Prince William and Kate Middleton were recently spotted at Balmoral Castle, where the royal family traditionally gathers during their summer break. However, Prince Harry and Meghan were not invited to the Scottish Highlands this year, sources told PEOPLE.

Despite a positive meeting between Harry and his father in February following King Charles’ cancer diagnosis, their communication has since deteriorated. Those close to the Duke of Sussex say the monarch no longer takes his son’s calls or answers his letters.

“He gets ‘unavailable right now,’ ” says a friend of Harry’s. “His calls go unanswered. He has tried to reach out about the King’s health, but those calls go unanswered too.”