Madeleine McCann's parents say they have "no doubt" that the Portuguese authorities will eventually reopen their investigation into her disappearance.
In a series of interviews to mark the fifth anniversary of her disappearance, Kate and Gerry McCann also said their seven-year-old twins Sean and Amelie have pledged to join the search for their big sister when they are older.
Madeleine was nearly four when she vanished from her family's holiday apartment in Praia da Luz in the Algarve on May 3, 2007 as her parents dined at a tapas restaurant with friends nearby.
On Wednesday the couple spoke of their renewed hope that she will be found alive and said they have received a major boost from Scotland Yard's review of the case.
Gerry McCann, 43, said: "I'm certainly more confident now than at any point for the last four-and-a-half years that we actually will find Madeleine and who is responsible."
He added: "I think the most important thing is that a lot of the investigation opportunities are in Portugal.
"I think it's fairly clear that the case will have to be reopened for those to be pursued adequately.
"We weren't expecting a knee-jerk reaction by any means. This is an ongoing dialogue, and I am sure the investigation will get opened again in due course. I have no doubt about that."
The officer leading Scotland Yard's review of the original investigation into Madeleine's disappearance spoke last week of his belief that the mystery can still be solved and said there is evidence she may still be alive.
Detective Chief Inspector Andy Redwood said the Metropolitan Police would like the case to be reopened but stressed that the decision was one for Portugal.
But Portuguese police responded by saying they had found "no new element" to justify relaunching their inquiry.
Referring to the Portuguese authorities' apparent reluctance to resume their investigation, Gerry McCann said: "The only way everyone will be able to move on is for the case to be solved, and that is for Madeleine to be found and the perpetrators brought to justice.
"Then everyone can move on. Until then, it's not going to go away. It can't go away."
The official Portuguese investigation into the case was formally shelved in July 2008, although private detectives employed by the McCanns continued the search.
Scotland Yard's review of the case, called Operation Grange, was launched last May after a request from Home Secretary Theresa May supported by Prime Minister David Cameron.
The Met team has already sifted through 40,000 pieces of information and identified 195 potential leads.
Gerry McCann said the Scotland Yard review was "a huge burden off our shoulders" and stressed that the British detectives have uncovered new information that could lead to Madeleine.
"For them to have already identified 195 investigative opportunities - and they aren't halfway through the material yet - does give us a lot of hope," he said.
The couple, from Rothley, Leicestershire, said Sean and Amelie are aware of Thursday's sad anniversary but are "absolutely fine" despite the disappearance of their older sister when they were two.
Gerry McCann said: "It's very matter of fact for them, because I suppose they've grown up with Madeleine missing. It's part of their life."
His wife, 44, spoke of wanting to protect the twins, recalling that Sean said to her about 18 months ago: "Shall I come and work for you and find Madeleine when we get older?"
She said: "I still go through that pain, the sadness, anxiety, frustration and anger. It's an awful thing to go through.
"I know how much it's devastated us, and I really don't want Sean and Amelie to have to suffer like that...
"I don't really want them to have the burden of this, of having to keep looking and looking and looking, and not being able to stop. So we need to find her now."