The Senate's No. 2 Republican said Tuesday that he opposed a vote this year on President Barack Obama's signature arms control treaty, dealing a blow to a top White House foreign policy priority and possibly to U.S.-Russian relations.

Senate Minority Whip Jon Kyl of Arizona said there wasn't time to deal with his concerns over a treaty that would cut U.S. and Russian strategic nuclear weapons deployments by about one third and restore weapons inspections that were halted nearly a year ago. Treaty ratification requires 67 votes...