Washington ? President Bush and Bruce Willis launched a new effort to persuade would-be parents to adopt foster children. But it was Willis who flubbed his lines, not Bush.

The actor and the president teamed up Tuesday to convince more people to reach into the growing ranks of often difficult-to-adopt foster children when building their families.

Whether prospective parents have grown pessimistic of their chances of adopting in the United States or have already begun looking overseas, a new television ad and Web site are aimed at encouraging them to reconsider and “to examine their hearts to find a place in their home for a waiting child.”

The president said he understands that adoption itself can be a frustrating and lengthy process, and that raising an adopted child can “add to the normal challenges of one’s daily life.” But, “Adoption changes a single life forever, and it brings countless blessings to the lives of parents,” Bush said.

Bush premiered a new public service advertisement featuring first lady Laura Bush and Willis, a longtime Bush supporter who also agreed to serve as a national pitchman on behalf of foster children.

“We all know Bruce is a tough guy in the movies. Truth of the matter is, he has a tender heart,” Bush said.

As Bush spoke, Willis grinned and winked at his three girls, who were sitting in the front row with ex-wife Demi Moore. Willis approached the White House last year to offer his services on the issue.

“Too many children in foster care are falling through cracks,” said Willis, who repeatedly mangled his brief remarks.

In the spot, Willis urges viewers to “Be a hero take the time learn about adoption today.”

“Looks like one of those Oscar-winning performances to me,” the president quipped.