It said the Saturday night attack on the Balzi Rossi restaurant killed five and injured 19, adding that its Italian chef and his staff were unhurt only thanks to a Russian security guard's "vigilance and selfless dedication to his professional duty".
There was no immediate comment from Ukrainian authorities.
The National Anti-Terrorism Committee, which co-ordinates various security agencies, initially reported a lower death toll in a statement issued shortly after the attack.
It said the bomb killed three people, including a woman who carried the explosive device into the restaurant, a guard who stopped her and a guest inside.
It said 21 others were injured when the bomb detonated near the restaurant's entrance.
The committee did not say who was the target or name the mastermind.
Moscow mayor Sergei Sobyanin on Sunday described the bombing as a "brutal terrorist act" but did not say who was responsible for the blast at the upscale restaurant, which is located on the ground floor of a high-rise apartment building that is one of seven skyscrapers in the city that date to the era of Soviet dictator Josef Stalin.
The Russian foreign ministry reposted the embassy statement without comment.
It did not respond to a request for comment or explain the higher death toll.
Several Russian media outlets claimed the bombing targeted a Russian general who was celebrating his birthday at the restaurant.
Some reported that the general was Colonel General Alexander Chaiko, who led the troops that made a botched attempt to storm the Ukrainian capital in 2022 and recently was appointed the chief of Russia's aerospace forces.
The reports could not be independently verified.
The business daily Kommersant reported that the bomb, hidden in a gift box, was probably detonated remotely and the woman carrying it could have been unaware of the content.
Kommersant said the bomb contained about 1 kilogram of explosives and contained metal balls for lethality.
Russian authorities have blamed Ukraine for a series of bombings and other attacks against senior military officials after the Kremlin sent troops into Ukraine in February 2022.
Earlier this year, Russia's Federal Security Service said authorities would tighten security around senior military and government officials following the attacks.
In February, Lieutenant General Vladimir Alexeyev, the deputy head of the GRU military intelligence service, was shot three times at a Moscow apartment building, but survived.
Ukraine denied its involvement.
In December, a car bomb killed Lieutenant General Fanil Sarvarov, head of the Operational Training Directorate of the Russian Armed Forces' General Staff, in southern Moscow.
Ukraine refrained from comment.
In April 2025, another car bomb that Russia blamed on Ukraine killed Lieutenant General Yaroslav Moskalik, a deputy head of the main operational department in Russia's General Staff.
Ukraine did not claim the attack but hinted at its involvement.
And in December 2024, a bomb hidden in a scooter killed Lieutenant General Igor Kirillov, who headed the Russian military's nuclear, biological and chemical protection forces, one of the few attacks Ukraine openly acknowledged.
Among other prominent victims of bombing attacks in Russia were Daria Dugina, the daughter of influential nationalist thinker Aleksandr Dugin, and Vladlen Tatarsky, a well-known pro-Kremlin military blogger.
Ukraine denied involvement in the attack on Dugina and remained coy about the attack on Tatarsky.