The US has confirmed that the incident was a 'green-on-blue' attack.
'The omission of the First Gentleman of Luxembourg name is blatantly disrespectful,' a Facebook user said.
Gauthier Destenay married politician Xavier Bettel in 2015.
Is this the most awkward handshake in history or the most aggressive?
Donald Trump has regularly criticised the EU and NATO for not spending enough on defence.
Trump has set himself up for some awkward meetings during his first overseas tour.
"A strong military is only possible with a strong economy," Prime Minister Theresa May will say.
Trump will use the trip to rally support against Isis and lobby for Middle East peace.
The UK barely hits Nato's defence spending target of 2% of GDP. But it's time to spend 6%.
US House speaker praises 'special relationship' and wishes Britain luck on election
US president pledges support for military alliance he previously dismissed.
A special centre will be set up in Helsinki to conduct research on thwarting such attacks.
DSG Technology has reportedly sold ammunition to international militaries and courted US interest.
IPv6 might enable more IP addresses, but it also lets hackers set up undetectable communication channels.
Unlike the US president, the Secretary of State has voiced a tough stance against Moscow.
Those working in his office have been told 'not to speak to him directly — or even make eye contact.'
Shadow defence secretary spoke to IBTimes UK after Theresa May invoked Article 50 of the Lisbon Treaty.
US president has been critical of alliance members not paying their share of Nato's budget.
US Secretary of State opened meeting of the ministers of the global coalition on the defeat of Isis.
Announcement comes after US Secretary of State decides not to attend his first NATO meeting in April.