Fearing they will be left out of a growing economy, US companies are calling for an end to sanctions on Burma but are facing a cool reception from policymakers and human rights groups.

US firms had long been shy about openly seeking to enter the resource-rich nation – a perennial top violator of human rights on annual lists – and the few companies that do business there have faced a backlash from activists.

But Burma has embarked on reforms over the past year that have surprised even critics, leading the EU and Canada to suspend most sanctions and Japan to step up assistance. China already has an outsized role in Burma’s economy after two decades of western sanctions.

In a letter to President Barack Obama, leading US business groups urged his administration to go beyond announced plans for a limited easing of sanctions such as allowing US credit cards in the country.

“Permitting certain US sectors to invest while excluding others will not prevent those sectors from being developed in Burma,” said the letter signed by the US Chamber of Commerce, American Petroleum Institute and US-ASEAN Business Council among other groups.

“It will simply ensure that our competitors fill the void, as they are already doing, and that jobs which could be given to American workers will go to workers in Asia and elsewhere,” they wrote.

Clay Thompson, director of corporate government affairs at Caterpillar Inc., said that the US equipment giant expected strong growth as Burma builds its infrastructure.

Thompson said Caterpillar had essentially ceded business to Chinese competitors, even though the US company supported restrictions on dealing with specific people or businesses blacklisted for wrongdoing by the Treasury Department.

“We’re coming to the view – along with, I think, several important voices in the US government – that at this point the sanctions are impeding the reform rather than driving it,” Thompson told AFP.

“What reformers in the country now really need is economic growth, which will certainly come if US companies are allowed to provide financial services and invest there,” he said.

The Obama administration has been at the forefront of diplomacy on Burma, entering talks in 2009 aimed at ending the country’s long isolation.

Since taking office a year ago, President Thein Sein has freed prisoners, opened dialog with rivals and allowed an election that gave democracy icon Aung San Suu Kyi a seat in parliament after years under house arrest.

Kurt Campbell, the assistant secretary of state for East Asia, recently told Congress that the United States needed to maintain “leverage” to press for further actions, such as pressing the military to end ethnic violence.

While saying that US firms had the “right values” and governance to promote reform, Campbell said that the administration wanted to move in a “careful” way and did not plan a full-scale lifting of sanctions.

In their own letter to Obama, rights groups including Human Rights Watch and the AFL-CIO, the leading US labor confederation, backed “the broad position” of the administration but voiced fear it would move too quickly.

The groups said that each step in easing sanctions should be linked to measurable progress on goals, including the release of remaining political prisoners, the end of abuses in ethnic-minority areas, and the fairness of elections due in 2015.

Aung Din, a former political prisoner who heads the US Campaign for Burma advocacy group, said there was a vital need to maintain pressure as Suu Kyi’s National League for Democracy only was allowed to seek a small number of seats in parliament.

“I hope US business leaders look at my country beyond business opportunities,” he said.

“There are millions of people who have sacrificed so much in their lives to achieve democracy, human rights, equality and permanent peace. They are more than a market,” he said.

Some US companies already have interests in Burma. A subsidiary of Chevron holds a minority share in an offshore gas field operated by France’s Total, due to a loophole that allowed US firms to maintain businesses that were in the country before sanctions took effect.

The Asian Development Bank projects that Burma’s economy will grow 6.0 percent this year after 5.5 percent last year due in part to foreign money coming in.

Changyong Rhee, the Manila-based bank’s chief economist, told AFP on a visit to Washington that the foreign cash gave Burma a chance to address key concerns such as building its infrastructure and improving its tax base.

“If you just rely on foreign capital, you never known what will happen. So foreign capital gives you time for your domestic resource mobilization,” he said.