While Treasury Secretary Jack Lew said the Treasury Department was looking to see what it could do to stem the tide of corporate tax inversions, Rep. Chris Van Hollen, D-Md., told CNBC on Monday that the "whole issue" can only be addressed in legislation.
"I do hope the White House will take whatever action they can using executive authority to reduce the value and benefits of these inversions until Congress acts," Van Hollen said in an interview with "Closing Bell."
Earlier Monday, Lew reiterated his call for legislative action to stop corporate inversion deals, where U.S.-based companies merge with a foreign competitor and then restructure and relocate tax domiciles to the lower-tax country. However, Lew said his office is investigating what it could do to help.
Read MoreTreasury's Lew urges action on inversions
"Congress may not move as quickly as necessary to respond to the growing wave of inversions. Given that, the Treasury Department is completing an evaluation of what we can do to make these deals less economically appealing, and we plan to make a decision in the very near future," Lew said in a speech at the Urban Institute, a Washington think tank.