LONDON (AP) -- FIFA came under pressure from sponsors Adidas, Coca-Cola and Visa on Wednesday to push Qatar to deliver reforms for migrant workers as the country rapidly expands to host the 2022 World Cup. The calls from high-profile commercial backers of soccer's flagship tournament came as Amnesty International's latest report found that Qatar is failing to make substantive changes to improve living and working conditions for low-paid laborers building its highways, hotels, stadiums and skyscrapers. FIFA maintained that the World Cup is proving to be a ''catalyst for significant change'' to labor laws in the tiny Gulf nation, which relies on more than a million guest workers, many of them drawn from South Asian nations including India and Nepal. But the statement from credit card company Visa is the strongest public expression of unease yet from a FIFA sponsor about the plight of workers in the tiny oil and natural gas-rich country. ''We continue to be troubled by the reports coming out of Qatar related to the World Cup and migrant worker conditions,'' Visa said in a statement. ''We have expressed our grave concern to FIFA, and urge them to take all necessary actions to work with the appropriate authorities and organizations to remedy this situation and ensure the health and safety of all involved.'' Adidas, the World Cup ball provider since 1970, said it remains in ''constant dialogue'' with FIFA and pointed to pressure already being applied on Qatar by soccer's governing body. ''There have been significant improvements and these efforts are ongoing, but everyone recognizes that more needs to be done in a collective effort with all stakeholders involved,'' Adidas said in a statement. FIFA financial accounts indicate that Adidas, Visa and Coca-Cola pay around $30 million a year to sponsor world soccer's governing body, which surprisingly selected Qatar as the first Middle East country to host the World Cup. Since the 2010 vote, Qatar has faced twin-pronged scrutiny over alleged corruption in the bid and conditions for low-paid migrant workers. Coca-Cola stressed in a statement that it ''does not condone human rights abuses'' but, like Adidas and Visa, did not threaten to withdraw its sponsorship over Qatar concerns. ''We know FIFA is working with Qatari authorities to address questions regarding specific labor and human rights issues,'' the Atlanta-based soft drinks manufacturer said in a statement. ''We expect FIFA to continue taking these matters seriously and to work toward further progress. ''We welcome constructive dialogue on human rights issues, and we will continue to work with many individuals, human rights organizations, sports groups, government officials and others to develop solutions and foster greater respect for human rights in sports and elsewhere.'' Qatar is yet to introduce long-planned labor reforms that could eventually end the controversial ''kafala'' system that ties migrant workers to a sponsoring employer. Rights groups have repeatedly urged Qatar to scrap the system, which is used throughout the Gulf, saying it encourages exploitation and abuse. FIFA said it continues to urge the Qatari authorities to abolish kafala but highlighted the need for international companies and governments to press for changes. FIFA President Sepp Blatter told Qatar's emir, Sheikh Tamim bin Hamad Al Thani, during a visit to Doha in March that the Gulf nation must do more to improve guest workers' lives. On a recent government-organized trip, The Associated Press spoke to guest workers crowded into bare-bones labor accommodations, which suggested many still are mistreated. Several workers spoke of paying hefty recruitment fees that are illegal under Qatari law. Some said they were duped into taking jobs at salaries well below what they were promised. ''Migrant workers have been working for many global companies in Qatar for decades, yet only now is real change happening in their working conditions,'' FIFA said in Wednesday's statement. World Cup organizers say there has not been a single death on one of their stadium projects, which are subject to international construction standards. ''Our hope is that these standards are extended to serve as a benchmark in the whole country,'' FIFA said. --- Associated Press Writer Adam Schreck in Dubai, United Arab Emirates contributed to this report.