Republican presidential candidate Mitt Romney said Monday he has given money to his campaign for a second time and may do so again before Saturday's fundraising deadline.

Romney declined to say how much money he had contributed although the financial reports he will have to release within weeks will reveal the amount. The second-quarter fundraising period for all candidates ends this week.

The former Massachusetts governor said an unprecedented $4 million that he spent on early advertising forced him to make the personal contributions. Romney's net worth is estimated at up to $350 million.

Romney spoke to reporters as his supporters sought contributions from their friends and business colleagues at a Boston event.

In January, Romney gave $2.35 million to his campaign, helping to boost his first quarter total to $23 million, the largest fundraising amount in the GOP field.

"My message is important and critical to get out in this country, and I recognized that there are a lot of people making big contributions," Romney said. "It would be nice not to have to loan or contribute to your campaign. But the reality is if you want to have a strong campaign that gets out there and can talk across the nation, your going to have to do what's necessary."

In January, Romney, a former venture capitalist, said it would be a "nightmare" if he had to contribute money to his own presidential campaign,

"It is a nightmare; I don't want to," he said Monday when asked to square his contributions with his prior statements.