The parents of 4-year-old Madeleine McCann took their campaign to find her to Spain on Friday, where they met with a government minister and issued an appeal for help.

Madeleine disappeared on May 3, when her parents left her and her 2-year-old twin siblings in their hotel room while they dined at a restaurant in their hotel complex in Praia da Luz, a resort town in Portugal's Algarve region.

Since then, parents Kate and Gerry McCann have launched an international campaign with the aid of celebrities such as soccer star David Beckham and J.K. Rowling, author of the Harry Potter series, in the hope of finding the girl. The couple had a brief meeting with Pope Benedict XVI on Wednesday.

Gerry McCann said they traveled to neighboring Spain in an effort to prompt anyone who might have any information to come forward.

"We are here to ask the Spanish public for help and we really are imploring for that help because we feel it is possible that Madeline was moved from Portugal, possibly into Spain, although we are not certain of that," he said at a news conference.

"We do realize that there are other families in Spain that have had similar experiences, particularly the young boy Yeremi from Gran Canaria and our thoughts and prayers go out to his family, and any other family that are in a similar situation to us," he said.

He was referring to Yeremi Jose Vargas Suarez, a 7-year-old who vanished in March in the Canary Islands and remains missing.

"We do feel that these type of disappearances should be considered in a pan-European fashion, the same way that other European Union movement of people is considered," McCann said.

He added: "I would like some reassurance in Spain that there has been some proactive investigation regarding Madeleine's disappearance.

"I think it is at least worth exploring the possibility that Madeleine's disappearance should not be considered in isolation and in the context of other disappearances in the Iberian peninsula, even the Canary Isles as well," he added.

The couple unveiled a poster with the now-familiar face of Madeleine and bearing an appeal for information in Spanish. They sat in front of a large billboard showing Madeleine's face and giving the emergency services number 091. Across the top of the billboard were the words "Mirame a los ojos", or "Look into my eyes."

The father said the couple was heartened by the work being done by the children's' ombudsman in Madrid and an association against child pornography, who he said had distributed Madeleine's image and publicized the child's disappearance.

The McCanns, who arrived in Madrid late Thursday, met privately with Spain's Interior Minister, Alfredo Perez Rubalcaba, after the press conference but declined to speak to reporters afterward. The ministry would not comment either.

Saying they do not plan to return to Britain without their daughter, the parents also plan trips to Germany, the Netherlands and Morocco. The couple are believed to feel these countries are important because they are either close to the Algarve or have a population which travels to southern Portugal for holidays.

Last week, Portuguese police announced they were searching for a white man aged between 35 and 40, who was wearing a dark jacket and light beige trousers and who was possibly carrying a little girl on May 3 in Praia da Luz.