"In the Syrian city of Deir ez-Zor because of the situation on the ground people must be provided [with humanitarian aid] by air bridges. If both parts of Aleppo are not enough provided with humanitarian aid, we must probe the possibility of [delivering] aid, especially medical goods, by air," Steinmeier told Welt am Sonntag newspaper.
He also called on parties of the Syrian conflict to take necessary measures to protect civilians.
Syria has been mired in civil war since 2011, with government forces loyal to President Bashar Assad fighting a number of opposition factions and extremist groups.
On February 27, a US-Russia brokered ceasefire came into force in Syria. Terrorist groups such as Islamic State (IS, also known as Daesh), as well as Jabhat Fatah al Sham (also known as Jabhat al-Nusra, or Nusra Front) are not part of the deal. Both groups are banned in Russia and a range of other countries.