Some of the 250 US troops participating in the annual joint military exercises called "Balikatan 2006" began arriving over the last few weeks.
The counterterrorism exercise, to begin later this month, will also focus on the delivery of medical and engineering services to Sulu, a stronghold of al-Qaeda-linked Abu Sayyaf militants.
"We need the (Philippines)-US Balikatan in Sulu," read placards at Saturday’s gathering in downtown Jolo.
Sultan Sharif Ibrahim Ajibul Mohammad Pulalun, the sultan of Sulu and North Borneo, said the exercise is "a golden opportunity" for the people to benefit from health services, road repair and school building projects provided by the US troops.
"I appeal to every Muslim, young and old, to welcome our American visitors and to support their peaceful cause. After all, we are the beneficiaries from these humanitarian projects," said Pulalun, who organized the rally.
"Let us not throw away what is in store for our fate. This is a chance that we can move on from the poverty that breeds terrorism," he told the crowd. "Let us be united and show to the world we are peaceful citizens."
Dozens of Muslim activists last week demanded that US troops leave Jolo, burning a mock US flag and raising anti-US placards, including one that read "Bud Daho, never again," referring to a Jolo area where US forces bloodily crushed a Muslim uprising about a century ago. The incident remains an emotional sore point among many Muslims.
Pulalon said he has been exerting efforts to explain the purpose of the joint military exercises to residents who remain opposed to their conduct.
"Let us give them the chance to help us because the local government alone has not enough funding to help us fast-track the needed services and development," Jolo Mayor Al-Khamer Izquierrdo appealed.
Pulalon said he asks nothing in return for organizing the rally "but I humbly appeal to the United States of America and the Philippine government to help our poor people and give them access to basic services such as education and health."
Security is a key concern during the US exercises because of the presence of Abu Sayyaf militants and a proliferation of unlicensed firearms on Sulu.
The Abu Sayyaf, which is on a US list of terrorist organizations, has been blamed for deadly bombings and high-profile ransom kidnappings, including of several Americans.
Mindful of the recent anti-US anger whipped up by an ongoing rape case involving four US marines, the US government has ordered its military personnel to respect Filipino culture and sensitivities as well as avoid running afoul of the law.
"US personnel will be considerate of Philippine customs and will not engage in behavior, wear any clothing or make any statement which may offend a Filipino," the order directed.
US soldiers were also barred from going on liberty leave to ensure they do not get into trouble with the law.
The rape case is seen as a black mark against the US military exercises that have been credited with helping weaken the Abu Sayyaf.
The four marines took part in large-scale military exercises with their Philippine counterparts in the former US naval port of Subic Bay late last year.
They were on shore leave on November 1 when a 22-year-old Filipina accused them of raping her inside a van while she joined the soldiers on a bar-hop.
The soldiers insisted that only one of them had sex with her and that the act was consensual.
The Philippine government sought custody of the marines, who are being held at the US embassy, after the Olongapo City regional trial court issued warrants for their arrest.
Washington rejected Manila’s request, invoking the Visiting Forces Agreement (VFA). However, the US decision infuriated many, including many lawmakers, and set off small but noisy anti-US street protests.
The 1999 security accord allows US forces to hold training exercises in the Philippines as well as governs the treatment of US soldiers who run afoul of the law.
The rape case sparked calls for the scrapping of the accord. — With AP, John Unson, Rainier Allan Ronda, Pia Lee-Brago