President Obama said Thursday evening that he will not campaign for any candidate that doesn't back up his efforts on gun control, a major focus of his last year in office.
"I will not campaign for, vote for or support any candidate, even in my own party, who does not support common-sense gun reform," Obama wrote in a New York Times op-ed.
Those measures would expand background checks for some gun sales, tighten enforcement of existing laws and take steps to curb gun violence.
Hillary ClintonHillary Rodham ClintonFederal, state courts at odds on Michigan recount Denzel Washington blasts media for selling 'BS' Trump opening act questions Clinton's popular vote lead MORE, the Democratic presidential front-runner, earlier this week praised Obama's gun action. Clinton has also argued that her primary rival for the Democratric nomination, Sen. Bernie SandersBernie SandersSanders: GOP blocked 'Trump proposal' to lower drug prices Pentagon's suppressed waste report only tip of the inefficient machine Weather Channel strikes back at Breitbart MORE (I-Vt.), isn't tough enough on guns.
Clinton seized on the issue toward the end of last year in the wake of a series of high-profile mass shootings,
Gun violence is expected to be a focus of Obama's last State of the Union next week.
Obama's message to candidates comes just weeks before ballots are cast in the early voting states of Iowa and New Hampshire, where Clinton and Sanders are battling.