DAVAO, Philippines -- The Philippine president says he became a local millionaire at a young age due to inheritance and reiterated he has no unexplained wealth as alleged by his leading critic, who questioned his claim that he was born into an impoverished family.

President Rodrigo Duterte gave some details of his personal assets at a dinner with journalists Friday in his southern home city of Davao, repeating a pledge to immediately resign if anybody can prove that he has questionable wealth concealed in bank accounts.

Duterte said his parents owned land in Davao where a profitable ice plant stood, and that he and his siblings divided the family assets after his father, a former Davao provincial governor, died in 1968. Duterte mentioned without elaborating that his family then was also involved in logging.

He said he suggested that the inherited landholdings be sold due to squabbling among the Duterte siblings.

"When we divided, we had our first millions already," Duterte said. "Long ago, I was just a student, fourth year. I already had about 3 million (pesos, or $59,000)."

Duterte mentioned a local bank, now closed, where he said he had cash deposits years ago, adding that his critics could still check the records of that bank. "If you want to really to trace my money, start from there," he said.

All his remaining landholdings are now in the name of his children, Duterte said. He added that he currently has only about 500,000 pesos ($9,800) in the bank, but did not provide other specific details of his other properties. His last public assets declaration put his worth at more than 27 million pesos ($529,000) as of December last year.

Opposition Sen. Antonio Trillanes IV has accused Duterte of concealing more than 2 billion pesos ($39 million) in undeclared bank accounts when he served as a top Davao city official, contradicting, the senator said, the president's claim that he came from an impoverished family. Philippine law requires officials to declare their assets and liabilities each year, and those who fail to do so could face dismissal from office.

In past interviews and speeches, Duterte has said he was born into a poor family but later walked back on those remarks, saying he and his siblings have inherited properties from his father even though they lived a modest life.

Trillanes has repeatedly called on Duterte to sign waivers so investigators could check his allegations that the president had concealed wealth in Philippine banks, some in joint accounts with his daughter, which he said were not publicly declared in the past in violation of the law.

Duterte has denied the allegations. "You show any bank account, foreign, and I will step down tomorrow," the president said.

He repeated an earlier accusation that it was Trillanes who has undeclared foreign bank accounts, mostly joint accounts with Chinese associates, citing information that the president said was given by an unspecified foreign government.

Known for bombastic speeches, Duterte acknowledged earlier in the week in a state TV talk show that at least one of the foreign bank accounts he earlier alleged belonged to Trillanes "was nothing, just a product of my mind." Duterte said he was still in the process of obtaining evidence against the senator, who he called "a liar."

Duterte won the presidency with a wide margin last year on a promise to eradicate crime and corruption. Despite growing alarm against his brutal crackdown against illegal drugs, which has left thousands of suspects dead, Duterte has remained widely popular in a poor country long exasperated by corruption and crime.