Angelina Jolie traveled to the tiny Italian island of Lampedusa on Sunday to thank its residents for welcoming in the estimated 20,000 migrants who arrived after fleeing unrest in Tunisia and Libya.

Jolie, a goodwill ambassador for the U.N. High Commissioner for Refugees, toured a migrant holding center, chatted with some refugees and then participated in a ceremony at Lampedusa's memorial for migrants lost at sea as part of commemorations for World Refugee Day on Monday.

"It is very hard to imagine looking out at this beautiful sea how many people have risked their lives and how many people have risked their children's lives and so many of them have lost their lives at sea," she said.

She thanked the residents who gathered for the ceremony for welcoming the migrants in and asked them to consider how "horrible" their lives must have been that they would risk everything for the chance of a better life in Europe.

"Can you imagine how it must feel to finally cross in" to Italy? she asked. "For the coast guard to save them and carry them to safety, save their children's lives and give them a chance to survive and to have a future, and what it means to them," said Jolie, wearing a plain black blouse and jacket.

U.N. refugee chief Antonio Guterres also was on hand to urge Europe to continue keeping its doors open to refugees. Italy's center-right government has begrudgingly accepted the migrants. It has also struck deals with Tunisia and the Libyan opposition to return those who don't qualify for asylum.

Guterres said the debate in Europe about immigration "doesn't correspond to the reality," given that the number of African migrants who have arrived in Europe is a fraction of the numbers who have gone elsewhere, such as Tunisia or Egypt.

"Obviously, for a small island like Lampedusa, to have such a large number of people coming is a huge pressure," he told reporters. "But for Europe as a whole, it is a drop in the ocean, and so I believe that with an adequate form of solidarity this challenge can be overcome."

Lampedusa, with a permanent population of 6,000, was overwhelmed this spring by waves of refugees fleeing the social uprising in Tunisia, with an estimated 20,000 arriving on the island, which is closer to Africa than mainland Italy. Boats continue to arrive from Libya, but eventually the refugees are transferred to holding centers elsewhere in Italy or sent back home unless they qualify for asylum.

Pope Benedict XVI urged countries to welcome refugees for as long as they need sanctuary in a message delivered Sunday while visiting the tiny republic of San Marino, itself founded in the early 4th century by a Christian refugee from Croatia.

"I invite civil authorities and every one of good will to guarantee a welcome and dignified living conditions for refugees until they can return to their countries freely and safely," Benedict said.

Yet as he spoke, members of Premier Silvio Berlusconi's government heated up the anti-immigrant rhetoric during an annual rally of the xenophobic Northern League party near the northern city of Bergamo.

Interior Minister Roberto Maroni drew cheers from the crowd when he boasted of the hardline policies he has pushed through to return migrants back to their home countries.

Amy Winehouse canceled part of her European tour on Sunday, a day after the British singer was heavily booed for being late and displaying erratic behavior on stage during a concert in Serbia.

The concert late Saturday in the Serbian capital of Belgrade kicked off what was to be a 12-date tour of Europe. But Winehouse decided to cancel appearances in Istanbul on Monday and in Athens on Wednesday, according to a statement from publicity company Outside Organization.

Her representatives said it would be "worked out as soon as possible" whether she would attend the rest of her European tour. The next scheduled concert date after Athens is July 8 in Bilbao, Spain. The tour was to end in Bucharest, Romania, on Aug. 15.

Winehouse would like to say sorry to fans expecting to see her in Turkey and Greece, but "feels that this is the right thing to do," the statement said.

"Despite feeling sure that she wanted to fulfill these commitments, she has agreed with management that she cannot perform to the best of her ability and will return home," it added.

There was no further explanation for exactly why Winehouse was canceling.

But Winehouse, who has publicly struggled for years with drug and alcohol issues, was jeered as she performed in Belgrade. She arrived almost an hour late before stumbling to the stage and appearing unable to remember the lyrics to her songs. She dropped the microphone, mumbled through her songs and occasionally disappeared, leaving her band to keep on playing.

A video posted on YouTube shows Winehouse wildly staggering around while trying to sing and stopping several times in mid-verse, looking over to her bandmates for help. At one point, she calls over a backup singer to fill in for her.

Serbian media described the concert before 20,000 fans as a "scandal" and a "disaster." The Blic daily said the concert was "the worst in the history of Belgrade."

The crowd at Belgrade's Kalemegdan Park could hardly tell which song Winehouse was singing and responded angrily. Many walked out in disappointment.

"It was horrible," said Ivana Bilic. "She should have canceled the whole thing, rather than appear at all like this."

The Daily Blic posted a clip from the concert on its website, commenting, "Listen if you dare."

Tickets cost about euro40 ($57) — very expensive in the country where average salaries are about euro300 ($428) a month.

Winehouse recently spent a week at a rehab program in London. Her 2006 breakthrough album "Back to Black" won five Grammy Awards, but her music in recent years has been overshadowed by her drug use and run-ins with the law.