KIEV, Ukraine — Pulling back a huge aid convoy whose entry into Ukraine stirred Western outrage, Russia on Saturday cheered the completion of what it called a successful humanitarian mission, while Chancellor Angela Merkel of Germany visited the Ukrainian capital and pledged more than $690 million for the rebuilding of war-ravaged areas of eastern Ukraine and aid to refugees.

The German pledge, the latest in a series of European offers to assist Ukraine since the toppling of President Viktor F. Yanukovych in February, signaled a desire by Europe not to allow Russia to become the sole benefactor of the Russian-speaking eastern portion of Ukraine.

It was accompanied by warnings from Ms. Merkel that the government in Kiev could not subdue pro-Russia rebels through force alone.

While denying that German calls for a cease-fire by all sides in the conflict implied a criticism of Ukraine’s increasingly bloody military offensive against the rebels, Ms. Merkel insisted that “there will be no military solution to this problem.”