"We've said before that we welcome steps towards justice in the Mumbai attacks. We've said many times before that we want to see the terrorists behind these attacks brought to justice," State Department spokesman Mark Toner told reporters here.
"My understanding is that he received due process in a full and transparent trial and the sentence was carried out," Toner said in response to a question.
The Washington Post also praised the Indian Government for carrying out this execution in secrecy.
"In a country where few things remain secret, where everything is argued in public, and where courts take decades to complete trials, Qasab's swift hanging was a welcome surprise for many," the daily said.
25-year old Qasab was hanged at 7.30 am in the Yerawada central prison in Pune yesterday.