Donald Trump poses with a ring given to him by a group of veterans during a Jan. 28 campaign event on the campus of Drake University in Des Moines. (Jae C. Hong/AP)

Donald Trump has fully made good on a promise to donate $1 million of his personal fortune to a veterans' charity, that charity's chairman said Wednesday.

"We got the check yesterday," said James Kallstrom of the Marine Corps - Law Enforcement Foundation. "It’s arrived, and it’s in the bank."

The presumptive Republican presidential nominee made his donation Monday evening, nearly four months after a fundraiser for veterans' causes that the candidate organized in Iowa.

At the January rally, Trump pledged to give $1 million of his own. Last week, Trump's campaign said he had already given that money away. In fact, he had not.

It was only late Monday -- after The Washington Post had made a public search for recipients of Trump's money on Twitter -- that the mogul actually moved to donate his money.

"He told me he’s going to give us a million dollars from the money that was pledged," said Kallstrom, a retired FBI official. He said Trump made a point of saying that the money came from his own accounts, not his Donald J. Trump Foundation, which has been largely funded by other people. The check reflected that, Kallstrom said: "It’s not his foundation. It’s just his personal account."

Kallstrom said he had no inkling that Trump was going to give this gift before he got that call.

Did he ask Trump why it had taken so long?

"I’m not going to ask that," Kallstrom said. "He’s a busy guy." Kallstrom said he "thanked [Trump] immensely."

The foundation provides help for the families of fallen Marines and federal law-enforcement officers, including $30,000 grants to pay for the education of their children. Kallstrom said that this was one of the larger gifts in the foundation's history, but not the largest.

In all, Trump said the Iowa fundraiser brought in about $5.55 million, of which at least $4.1 million has now been distributed to veterans' charities. The remainder is set to be given out by Memorial Day, Trump's campaign has said.