Russian planes and Syrian military forces have been bombarding rebel-controlled districts of Aleppo since an internationally brokered ceasefire collapsed last month.
The United States and some European countries have accused Russia and Syria of committing war crimes, which Russian officials deny
Russia insists it is working to achieve a peace deal for Aleppo.
Now, it has announced the Russian and Syrian armed forces will halt air strikes and shooting in the city for eight hours on Thursday to allow free movement of the sick and wounded.
Russian Defence Ministry official Lieutenant General Sergei Rudskoy has ruled out a longer cessation in the fighting, though.
"Given the situation, a unilateral ceasefire makes no sense, since Jabhat al-Nusra and groups allied to it will once again be given a breather, will regroup and restore their military capability."
The United Nations, which has been calling for weekly 48-hour humanitarian pauses in the fighting, has welcomed the announcement.
But spokesman Stephane Dujarric says eight hours is not long enough to get aid trucks in to deliver assistance.
"We will use whatever pause we have to do whatever we can. Obviously, there is a need for a longer pause in order to get trucks in and trucks rolling in. But, obviously, any pause is welcomed by the UN and by the inhabitants of Aleppo."
The announcement came as European Union foreign ministers met in Luxembourg to discuss the Syrian crisis.
In a statement, the bloc has condemned Russia's air campaign, saying it may constitute war crimes.
And the EU has promised to impose more sanctions on the Syrian government.
Foreign olicy chief Federica Mogherini has called for an immediate ceasefire in rebel-held eastern Aleppo.
"The priority is to stop the bombing of Aleppo. In this respect, we call on the Syrian regime and Russia to stop the bombing and avoid further humanitarian catastrophe."
About 275,000 people are believed to be trapped in the city, which UN Special Envoy Staffan de Mistura has warned is at risk of being reduced to rubble.
"Between now and December, if we are not finding a solution for Aleppo, Aleppo will not be there anymore. Any type of discussion that ignores Aleppo would be, frankly, something that history will judge us."
Emergency service workers say a family of 14 was among the victims of an air strike on an opposition-held area of Aleppo this week.
