Washington, Feb 28 (IANS): The US Friday slammed the killing of a Bangladeshi-American writer, offering help in the investigation.

"The United States condemns in the strongest terms the brutal murder of Avijit Roy, which was horrific in its brutality and cowardice," State Department spokesperson Jennifer Psaki told reporters at a daily news briefing, Xinhua reported.

"Avijit was a journalist, a humanist, a husband, and a friend, and we extend our condolences to his family and friends," she said, adding the US is ready to assist in the investigation, if asked.

Roy, 42, was hacked to death by two attackers wielding machetes in Bangladesh's capital Dhaka Thursday evening, when he was leaving a book fair with his wife, who was also wounded seriously in the attack, said media reports.

Roy was an engineer by profession, but had reportedly received death threats from Islamists for his articles advocating secularism.

Psaki said the motive to kill Roy was not known yet.