Sen. Bernie Sanders said at the White House on Thursday that he plans to compete in next week's D.C. primary, but he underscored that he "will work as hard as I can" to stop presumptive GOP nominee Donald Trump in the general election.

Sanders spoke after he met with President Barack Obama — three days after media outlets determined that Hillary Clinton had enough commitments from delegates to become the Democratic Party's presumptive presidential nominee and two days after her convincing victories in primaries in California and New Jersey.