She told The Times he was "an wonderful guy" who had come to the United Kingdom three years ago, with his brother Omar, "seeking a better, safer life".
He was trapped there for two hours, and made phonecalls to his friends and family in Syria to say goodbye.
Firefighters have said they expect the number of fatalities to rise and that they do not expect to find anymore survivors in the 1970s building.
Alhajali's friend and co-founder of the Syria Solidarity Campaign Abdulaziz Almashi confirmed the news, saying he had met Alhajali while working for the organisation, which promotes freedom, peace and democracy in Syria.
Mohammed Alhajali, 23, tried to leave his 14th floor flat with his older brother Omar as the horror unfolded, but the pair became separated on the way down and Mohammed returned upstairs.
He initially fled with his brother, Omar, before returning back to their flat alone.
Mr. Alhajali studied civil engineering at the University of West London.More news: Scotland striker Leigh Griffiths 'gutted' after England's last-gasp leveller
He worked for the Syria Solidarity Campaign in the United Kingdom, which calls for peace and democracy in the country.
The group said Mr Alhajali at one point was on the phone with a friend in Syria after unsuccessfully trying to get hold of his family in the country.
"We are heartbroken for his family, who thought he had found safety in the United Kingdom".
Omar was reportedly found in hospital where he is said to be in a stable condition, according to the group.
It remains unclear just how many people perished in the London tower fire tragedy.
The tower block went up in flames early Wednesday in what London Fire Brigade Commissioner Dany Cotton described as an "unprecedented incident".
The student arrived in the United Kingdom four years ago after fleeing his home in Daraa, Syria and crossing the Mediterranean Sea from Turkey.