"Melania and I will be going to the funeral of Pope Francis, in Rome," Trump wrote on his social media platform Truth Social.
"We look forward to being there!"
Pope Francis died on Monday morning aged 88 after suffering a stroke and subsequent heart failure, according to the Vatican.
The pontiff, who led the Catholic Church for 12 years, has opted to be buried outside the Vatican's walls, at Rome's Basilica of Santa Maria Maggiore, after initiating new rules for a more modest funeral ceremony before his death.
His funeral will nevertheless be a global event, with heads of state and government from around the world expected to attend.
Cardinals are due to meet in the Vatican on Tuesday to discuss the funeral arrangements, with the burial usually taking place four to six days after death.
Just hours before his death, Francis briefly met with Trump's deputy, Vice President JD Vance, on Sunday, who has made a number of trips abroad since the new administration took office.
For Trump, however, it would be the first foreign trip since returning to the White House on January 20.
It was initially unclear whether Trump would only travel to Italy to attend the funeral, or also visit other locations.
Italian Prime Minister Giorgia Meloni invited Trump to Rome when she visited the White House last week, saying he had accepted.
Trump had originally planned to travel to Saudi Arabia for his first foreign trip.
