The US defence secretary, Pete Hegseth, has announced that the execution of Nidal Hasan will be public. The Pentagon stated on Monday that Hasan, convicted of killing 13 people at Fort Hood in 2009, will be executed by firing squad.

Hegseth stated that there was no doubt about the decision. He said that Hasan must be executed by firing squad because, he said, he 'betrayed the country'. Hasan was described as 'a radical Islamist who killed many Americans'.

According to Hegseth, the execution will take place at Fort Hood on Thursday at 13:00. He explained that it will take place at the same time as Hasan began his attack, and it will be carried out by a firing squad. It will be the first execution by firing squad conducted by the US military since the Second World War.

Hegseth said: 'We will ensure that people can watch, that it is public, because people must understand that such acts have serious consequences.' He did not specify how the execution would be made available to the public. The Pentagon referred questions about the method of public broadcast to the army, which has not yet responded to the inquiry.

The decision to execute by firing squad was recommended by Hegseth and approved by President Donald Trump. The acting secretary of the army, Adam Telke, ordered that the execution take place on 3 December at 14:00 Eastern Time, or 13:00 local time at Fort Hood.

Hasan was sentenced to death in July 2013 for 13 counts of premeditated murder and 32 counts of attempted murder. At the trial, he told the panel of 12 officers that he targeted soldiers who were preparing to deploy to Afghanistan, as, according to his words, they were involved in 'an illegal war'. On the day of the attack, he entered the medical centre at Fort Hood and began shooting at soldiers undergoing pre-mission checks, following those who fled the building, and was subdued after a gunfight with police in which he was also wounded.

The US military last executed an individual on 13 April 1961, when Private First Class John Bennett was hanged for the rape and murder of a 10-year-old girl. The last execution by the US military was carried out in 1945, 81 years ago. Various US states have continued to carry out executions by lethal injection, but not the US military. Hasan's execution will be the first military execution by this method in 81 years.