The conflict between Ukrainian forces and Russia-backed separatists has claimed more than 10,000 lives since it erupted in 2014.
A cease-fire agreement signed in February 2015 in the Belarusian capital, Minsk, has failed to end the violence, which has recently flared up.
Germany and France have tried to convince both sides to implement the Minsk deal, but with little success so far.
Merkel and Macron said they were concerned that the security situation in eastern Ukraine had not significantly improved since they held a four-way telephone call with Russian President Vladimir Putin and his Ukrainian counterpart Petro Poroshenko on August 22.
"We urge President Putin and President Poroshenko to fully respect their commitments, to support the cease-fire in a public and clear manner, and to ensure that appropriate instructions have been sent to the military and local forces," they said in a joint statement issued by the chancellery in Berlin.
They said the cease-fire agreement was still violated too often, including with the use of heavy weapons.