West Steps Up Diplomatic Efforts to Avert Russian Attack on Ukraine

German Chancellor Olaf Scholz is traveling to Ukraine on Monday and Russia on Tuesday in the West’s latest diplomatic effort to avert a potential attack by Moscow on its neighbor, days before what the U.S. has warned could be the start of a Russian invasion.

Mr. Scholz, who has been in office since December, has been thrust to the center of negotiations between the U.S., Europe and Russia. He is following up on visits last week by French President Emmanuel Macron.

The trip comes amid increased alarm in the West after the U.S....