"We've seen a lot of interest from American energy companies interested in help building oil refineries and developing natural gas," Butenis said.
"The energy sector has been the biggest area of interest for US companies. I think that will remain," she said.
Butenis who is nearing her three year term in Sri Lanka said there has been a lot of interest and negotiations on US investment opportunities in the island.
"The business environment is right for American investments but sometimes it takes a little longer with government bureaucracy that is not true only in Sri Lanka"
"Within the next few years we will see more investment coming," she said.
Sri Lanka's rulers, who have violated property rights of both citizens and non-citizens repeatedly since independence from British rule, resumed the activity last year.
Micheal Delaney assistant US trade representative for South Asia told reporters earlier in the month that the US has been assured that there would be no more expropriations.
"We have expressed our concern about that to the government of Sri Lanka," Delaney said.
"It has been characterized to us as an exceptional one-off act. We have been encouraged not to see that as a pattern or any model for future action."
Following the passage of the law which legislators said was ad hominem and trespassing on the separation of powers between the legislature and parliament, the intention to re-take privatized plantations lands have been announced.
The plantations themselves were expropriated at one time. In many authoritative, fascist-nationalist or left-leaning states the energy sector has been a favourite target for expropriation.
On Monday Butenis visited a bottling plant of Coca Cola, a quintessential US brand, in Biyagama, in the suburbs of the Colombo.
Coca Cola, a key player in Sri Lanka's beverage industry has adopted a number of environment friendly initiatives aimed at improving water usage and cutting carbon emissions.
"Coke is a pre-eminent American company and I m proud of its successful operation in Sri Lanka", Butenis said.
I think they are setting standards in occupational safety and green technology" she said.