LONDON — Caught off guard by the crisis in Ukraine, NATO plans to create a “spearhead” rapid deployment force and a “more visible” presence in Eastern Europe to assuage concerns about Russian intentions, Anders Fogh Rasmussen, the alliance’s secretary general, was quoted as saying on Wednesday.

The United States, Germany and other key alliance members have signaled that they have no plans for any substantial new NATO military presence in the region and have been careful to avoid escalating military tensions with Moscow. But with NATO leaders scheduled to meet next week in Cardiff, Wales, the alliance appears eager to show a united front and to demonstrate the ability to respond quickly at a time when Russia stands accused of menacing Ukraine.

The plans described by Mr. Rasmussen seemed an attempt to balance those pressures.

In an interview with correspondents from six European newspapers, he said that while the proposal anticipated the prepositioning of supplies and equipment at new bases, it would not infringe on the alliance’s agreements with Russia, which have prevented substantial NATO buildups in the lands that joined the alliance after the collapse of the Soviet Union.

NATO’s strategy in response to Russian pressure on Ukraine has been to conduct more exercises, aircraft patrols and the like. Mr. Rasmussen suggested that the alliance now plans to augment those measures by increasing its preparedness to send more troops to Eastern European bases if necessary.