Guam offered Sunday to temporarily house thousands of Afghans being evacuated from their country as part of the US troop withdrawal, but insisted it be consulted on the planning.

In a letter to US President Joe Biden, Guam Governor Lou Leon Guerrero said she needed to be certain "these decisions reflect the best interests of our people".

US troops are expected to be out of Afghanistan by September 11 but lawmakers say it could take more than two years to process US visas for about 18,000 Afghan allies and their families.

There are fears that if they remain in Afghanistan they will suffer retaliation from the Taliban.

Veterans and human rights advocates have urged Washington to relocate the Afghans to Guam as a safe zone until their special immigrant visas are processed.

"I assure you that my administration is prepared to assist in executing your plans on this matter should Guam be chosen," Leon Guerrero said in her letter.

"If such a decision is made, I respectfully ask that I be part of critical discussions concerning Guam's role and any related task force should one be established.

Guam has been used as an evacuation destination before, housing Vietnamese refugees in 1975 before they were resettled in the United States
Guam has been used as an evacuation destination before, housing Vietnamese refugees in 1975 before they were resettled in the United States AFP / Tony AZIOS

"Due to the gravity and urgency of this matter, I would like to speak with you soon."

There has been mixed reaction in Guam to the possibility of again being used as an evacuation destination, after the Pacific US territory took in Vietnamese refugees in 1975 before they were resettled in the United States.

"I don't understand the reason to bring them to Guam. Guam is a small island," said 49-year-old Joseph Meyers.

"How many Afghans are we talking about? If just dozens, maybe that won't be so bad but if we are talking thousands, I don't think we can handle it."

But Nadia Holm, 40, said the United States had a responsibility to protect those who had assisted American forces.

"They have been loyal to the US. Their lives are at risk and we should protect them from harm," she said.

Michael San Nicolas, Guam's delegate to the US Congress, said any evacuation plan must include a condition that the refugees are vaccinated against Covid-19.