Chancellor Angela Merkel spoke with Russian President Vladimir Putin and Ukraine's Petro Poroshenko on the situation in Ukraine, the German government spokesman said.
The separate conversations came ahead of a meeting Monday in Berlin of the Russian, Ukrainian and German foreign ministers.
Merkel's talks concerned the situation in Ukraine and the Minsk agreement for a truce, government spokesman Steffen Seibert said in a statement.
"The chancellor expressed concern about the continuing tensions and the humanitarian situation in the east of Ukraine," he said.
In her conversation with Poroshenko, Merkel stressed her support in principle for a Normandy-style meeting of heads of state and government (grouping Russia, Ukraine, France and Germany) while linking the results of such a summit to "concrete progress".
At the end of December Poroshenko announced Normandy-style talks for January 15 in the Kazakh capital Astana.
Merkel stressed Thursday that the date of the meeting had yet to be confirmed "after discussions planned in the coming days".
"A substantial coming together of positions on a ceasefire and the establishment of a demarcation line are needed," Seibert said.
To Putin, Merkel also hoped that each party would contribute "quickly to make progress on the basis of the Minsk accords" signed in September.
On this point, Moscow should use its influence with pro-Russian separatists, Seibert said.
The Kremlin denies Ukrainian and Western charges of backing the rebellion in eastern Ukraine in order to extend its influence in the former Soviet republic after the ouster of a Moscow-backed president in February 2014.