Media playback is unsupported on your device Media caption President Obama, his wife Michelle and daughters Sasha and Malia, landed in Belfast, as Jane Hill reports

The road to a lasting peace in Northern Ireland is "as urgent now as it has ever been", the US president has said.

Barack Obama, on his first official visit to NI, addressed a gathering at the Waterfront Hall in Belfast, ahead of the G8 summit in County Fermanagh.

There was "more to lose now" than before but he vowed the US would back those who chose "the path to peace".

He was accompanied on his visit to Belfast by his wife, Michelle, and daughters Sasha and Malia.

Mr Obama told the audience of young people and dignitaries that he had wanted to come to Northern Ireland, describing it as a place of "remarkable beauty and extraordinary history".

Media playback is unsupported on your device Media caption President Obama said there were still "wounds that haven't healed and still many miles to go"

He said Northern Ireland was "part of an island with which tens of millions of Americans share an eternal relationship".

"If there's one thing on which Democrats and Republicans in America wholeheartedly agree, it's that we strongly support a peaceful and prosperous Northern Ireland," he said.

"But as all of you know well, for all the strides you've made, there's still much work to do. There are still people who haven't reaped the rewards of peace; who aren't convinced that the effort is worth it.

"There are still wounds that haven't healed, and communities where tension and mistrust hangs in the air. There are walls that still stand; there are still miles to go."

Image caption In a surprise move, President Obama and David Cameron drove through Enniskillen

He added: "If you continue your courageous path towards a permanent peace, and all the social and economic benefits that come with it, that won't just be good for you.

"It will be good for this entire island, for the United Kingdom, for Europe; and it will be good for the world."

The president said America would always "stand by" Northern Ireland.

"We will keep working closely with leaders in Stormont, and Dublin, and Westminster to support your political progress."

He added: "To those who choose the path of peace, I promise you, the United States of America will support you every step of the way.

"We will always be a wind at your back. And like I said when I visited two years ago, I am convinced that this little island, that inspires the biggest things - its best days are yet ahead."

Earlier, Mrs Obama addressed the audience and said the youth "might well be some of the most important people we meet during our visit".

Media playback is unsupported on your device Media caption Michelle Obama: "I have never felt more optimistic"

She added: "Standing here with all of you today, I have never felt more optimistic."

America's first lady then travelled to Dublin for a number of engagements.

Air Force One touched down at Belfast International Airport at about 08:35 BST on Monday.

All the G8 leaders - from the US, UK, France, Germany, Italy, Japan, Russia and Canada - are now in Northern Ireland.

Image caption The two leaders helped pupils at Enniskillen Integrated Primary School paint a G8 banner

Their two-day summit, focusing on issues such as Syria, trade and taxation, is being held at the Lough Erne golf resort, near Enniskillen, amid an unprecedented security operation involving thousands of police officers.

In a surprise move, Mr Obama and Prime Minister David Cameron drove through Enniskillen in a motorcade.

A small group of people were surprised to find themselves being waved at by the president as he entered the town via one of its bridges.

Analysis The decision to put both Prime Minister David Cameron and US President Barack Obama in the one vehicle and drive them through the Fermanagh countryside should not be underestimated. The advantage of the decision to Mr Cameron was that he got 30 minutes face time with the president as they journeyed to and from their engagement at an Enniskillen primary school. But the secondary benefit was the public message that No 10 wanted, that Northern Ireland, and in particular the far west of Northern Ireland, is safe enough to drive around in and that the threat from dissident terrorists is minimal.

The president and prime minister then went to an integrated primary school, attended by both Catholic and Protestant children, near Enniskillen.

Enniskillen Integrated Primary School was established in the wake of the 1987 IRA Poppy Day bombing, which killed 12 people.

The two leaders helped pupils paint a G8 banner.

In Enniskillen, the local education authority, the Western Education and Library Board, has encouraged schools to stay open and maintain a "business as usual" approach during the two-day summit.

Meanwhile, a protest against global policies linked to the G8 was held in Belfast.

Image caption A protest was held in Belfast ahead of the world leaders gathering in Fermanagh

The police said a small group of protesters made their way from the Falls Road to Belfast City Hall before returning to the west of the city on Monday.

A 19-year-old man was arrested for a number of offences, and fast-tracked through the courts.

He received a conditional discharge for disorderly behaviour, £150 fine for failure to remove a disguise and £150 for resisting arrest.

On Sunday, a 48-year-old man was arrested in Enniskillen on suspicion of criminal damage. He was later released.

Another protest was held on Lough Erne, County Fermanagh.