"I am doing everything that I can and will continue to do everything that I can to make sure that Donald Trump does not become president of the United States." | Getty Sanders to meet with Clinton on Tuesday

Bernie Sanders will meet with presumptive Democratic nominee Hillary Clinton on Tuesday night to press her on her policy positions and decide whether he can support her, Sanders said Sunday.

"I simply want to get a sense of what kind of platform she will be supporting, whether she will be vigorous in standing up for working families and the middle class, moving aggressively in climate change, healthcare for all, making public colleges and universities tuition-free," Sanders said on NBC's "Meet the Press." "And after we have that kind of discussion and after we can determine whether or not we are going to have a strong and progressive platform, I will be able to make other decisions."


The meeting will take place as returns are coming in from the final Democratic primary of the year, in the District of Columbia. Sanders vowed to compete in the D.C. after a disappointing finish in the California primary last week.

Sanders also hinted at the leverage he'll have at the Democratic National Convention, where he's expected to have at least 1,877 of the 4,765 delegates.

"What we have got to determine between now and the Democratic Convention, and by the way Chuck, we're going to have well over 1,900 delegates at that convention, is what kind of platform and what kind of agenda there will be if Secretary Clinton gets elected, if she wins the election," Sanders said.

Sanders dodged a question from "Meet the Press" host Chuck Todd on whether he was still as "active candidate" for president.

"Well, let me just say this," Sanders replied. "I am doing everything that I can and will continue to do everything that I can to make sure that Donald Trump does not become president of the United States."

Sanders has sounded more conciliatory notes after losing California, as top Democrats who had long resisted taking sides in the primary — including President Barack Obama, Vice President Joe Biden and Sen. Elizabeth Warren — have endorsed Clinton.

Sanders added on ABC’s “This Week” that he needed to see commitments from Clinton to progressive taxation, reining in Wall Street, guaranteeing health care coverage to all Americans and eliminating tuition at public colleges and universities. But he said Clinton couldn’t lead the “political revolution” that he has promised his supporters, no matter what positions she adopted.

“Well, I don't think Hillary Clinton can lead a political revolution,” Sanders told George Stephanopoulos. “But I think if Hillary Clinton is smart —and she certainly is smart — she will understand that good public policy, taking on the big money interests and standing up for working families, standing up for the environment, standing up for clean water, is, in fact, good politics.”