Armenian Prime Minister Nikol Pashinyan said 105 Armenian service personnel had died in clashes with Azerbaijan over the last two days, the Interfax news agency reported on Wednesday.
Armenia and Azerbaijan blame each other for the latest flare-up in the South Caucasus.
In a speech to Armenia's parliament, Pashinyan said Azerbaijan had "established control" over some parts of Armenian territory as a result of the latest military confrontation, the TASS news agency reported.
"If we say that Azerbaijan has carried out aggression against Armenia, it means that they have managed to establish control over some territories," he said, according to TASS.
Armenia had reported 49 fatalities on Tuesday, adding that the number was likely to rise. Azerbaijan reported 50 fatalities among its service personnel.
Pashinyan resisted calls from the opposition to introduce martial law in Armenia - as the country did two years ago during a bloody six-week war with Azerbaijan over the disputed Nagorno-Karabakh region - saying he did not yet think it necessary.
The fighting that broke out on Tuesday is the worst between the ex-Soviet republics since 2020.
(Reporting by Reuters; Editing by Kevin Liffey)