Lula says the call will be made next week during the annual UN summit in New York.
I'm going to the UN meeting to have a conversation with Trump and tell him: Don't interfere in the elections in Brazil, says Lula.
The Brazilian leader is expected to deliver a speech to the UN General Assembly on Tuesday.
Lula's opponent, the right-wing candidate Flávio Bolsonaro, is the son of the country's former president Jair Bolsonaro. Father and son Bolsonaro have strong ties to the Trump administration in the United States, and in May Flávio visited the president at the White House.
Brazil's presidential election will be held in October.
