Sarah Palin says residents of refugee camp 'are so full of joy', during visit tightly stage-managed by Christian relief group

Earthquake. Cholera. Political strife. And now Sarah Palin.

The former US vice-presidential candidate is visiting Haiti's refugee camps on a mission variously described as bringing great comfort to the people of the Caribbean country and an attempt to bolster her weak foreign policy credentials ahead of a possible run for the White House.

Palin arrived at the invitation of Franklin Graham, a leading evangelical preacher who has drawn criticism for calling Islam a "religion of war" and for saying that Barack Obama has "the seed of Islam" in him.

Haiti, still recovering from the devastating earthquake that killed 220,000 people nearly a year ago, has recently been hit by a cholera epidemic which claimed a further 2,000 lives and is enduring further upheaval over a contested presidential election that has led to violence on the streets of Port-au-Prince and calls in Washington to end US aid to the country.

Palin emerged from one of the refugee camps housing the hundreds of thousands of Haitians who are still without homes after the earthquake, and said: "They are so full of joy. We are so fortunate in America and we are responsible for helping those less fortunate."

This may not go down well with those in her Tea Party movement who regard aid to foreign countries as unnecessary.

Graham, the son of America's best-known evangelist, Billy Graham, said: "I believe Governor Palin will be a great encouragement to the people of Haiti."

He heads a Christian relief organisation, Samaritan's Purse, which is overseeing Palin's tightly stage-managed visit. It declined to reveal her itinerary and told reporters to leave its compound in Haiti before the former Alaska governor's arrival, saying it was under a "security lockdown".

Samaritan's Purse has been accused during other humanitarian crises of putting its evangelical mission ahead of more tangible assistance to those in need. The organisation raises large sums of money from US Christians but the proceeds are not always visible on the ground.

During the 1994 Rwandan refugee crisis, Samaritan's Purse was criticised by other aid organisations for spending large amounts on luxury accommodation for its staff and providing only minimal assistance as tens of thousands of people died of cholera. That assistance principally consisted of sending stretcher bearers to carry the sick for treatment as a third person ran alongside the victim reading passages from the Bible.

In 2001, Samaritan's Purse was scorned for requiring victims of El Salvador's earthquake to attend prayer meetings before they could receive aid.

Palin is reported to be considering trips to Britain and Israel next year to further bolster her foreign policy credentials. She has described Margaret Thatcher as one of her heroes.