Reports claim deal has been struck to admit Ali Abdullah Saleh, but White House denies permission has already been granted

Washington is considering a request to admit the politically besieged president of Yemen, Ali Abdullah Saleh, to the US following a vigorous debate within the Obama administration over whether the move will be seen as support for an Arab despot with blood on his hands.

Saleh, who has ruled for 33 years, said at the weekend that he plans to travel to the US to end the political crisis in Yemen that has claimed the lives of hundreds of anti-regime protesters.

"I would like to get away from attention and TV cameras and allow the consensus government and the local authorities to prepare properly the upcoming elections," he said.

But a dispute has broken out over the terms Saleh's admission, with the US saying he will only be allowed in for "legitimate medical treatment" for injuries sustained from a bomb attack on his presidential compound in June.

Some in the US administration are concerned that Saleh is looking for a way out of Yemen to avoid prosecution for his army's slaughter of ant-regime protesters earlier this year. Washington does not want to be seen to be giving Saleh asylum or protection.

However, other administration officials believe that Saleh's departure could open the way to an end to Yemen's political crisis.

The New York Times reported US administration officials as saying that Washington has decided in principle to admit Saleh. But the White House issued a statement saying no decision has been made.

"US officials are continuing to consider President Saleh's request to enter the country for the sole purpose of seeking medical treatment, but initial reports that permission has already been granted are not true," said a White House spokesman, Josh Earnest.

Washington has one eye on the decision by President Jimmy Carter to allow the shah of Iran to travel to the US in 1979, which contributed to the anger of Iranian revolutionaries who seized the American embassy in Tehran and took diplomats hostage.

Saleh said he only intends to be in the US for "a few days", and that he "will not abandon my people and my comrades". But opposition activists believe that if he leaves Yemen in the present political climate he will not swiftly return.

Saleh's opponents celebrated in June when he left for Saudi Arabia for treatment after the failed assassination attempt. Saleh returned home in September, however.

Following months of protests, Saleh signed an agreement last month to hand over powers to his vice president, Abed Rabbo Mansour Hadi, and to leave office after next year's election in return for immunity from prosecution for crimes during his rule, including the killings of anti-regime protesters.

The immunity deal has infuriated many of the regime's opponents, who say Saleh continues to wield considerable power through his relatives and political loyalists who retain office.

About 20 people were killed over the weekend in protests against the immunity deal in the capital, Sana'a, and the southern city of Taiz.

Tens of thousands of Yemenis took to the streets of Sanna on Monday to demand Hadi's resignation over his failure to bring to justice those responsible for killing protesters.

The New York Times reported that the US has set conditions, including requiring an itinerary, for issuing Saleh a visa. Although those conditions have yet to be met, officials said that Saleh could arrive in the coming days.