BURLINGTON, Vt. — Democratic presidential candidate Bernie Sanders said Thursday in an address to his supporters that he will work with Hillary Clinton to transform the Democratic Party, adding that his “political revolution” must continue and ensure the defeat of Republican Donald Trump.

Sanders said in a capstone livestream address to his political followers that the major task they face is to “make certain” Trump is defeated. The Vermont senator said he plans to begin his role in that process “in a very short period of time.”

“But defeating Donald Trump cannot be our only goal. We must continue our grassroots efforts to create the America that we know we can become,” Sanders said, pointing to his 1,900 delegates at the upcoming Democratic National Convention in Philadelphia.

Sanders spoke from his Vermont hometown a week after Clinton secured enough pledged delegates and superdelegates to become the presumptive nominee. He did not concede the race, nor did he refer to Clinton as the likely nominee, instead offering a lengthy list of policy proposals he hopes to see approved by the party.

The two rivals met Tuesday night at a Washington, D.C., hotel to discuss policy goals and future plans. Sanders said that while it is “no secret” that he and Clinton have “strong disagreements on some very important issues,” it was “also true that our views are quite close on others.”

He said he looked forward to additional talks between the two campaigns to ensure that his supporters’ voices are heard and the convention adopts “the most progressive platform” in the party’s history.