Investors should be cautious heading into the first U.S. interest rate increase in years, but any pause in the Fed's upward path presents a buying opportunity, strategist Jason Trennert said Tuesday.

Unlike past tightening cycles, the central bank is unlikely to hike rates steadily—for example, by a quarter percentage point at each meeting of the Federal Open Market Committee, the chief investment strategist at Strategas Research said. Instead, the FOMC will probably pause for a couple of meetings as it assesses how the next rate rise will affect financial conditions.