Story highlights The move comes after the Democratic Platform Committee adopted some of the Vermont senator's key positions

However, some of Sanders' supporters are still critical of this upcoming endorsement.

Washington (CNN) Bernie Sanders is positioned to officially throw his support behind Democratic rival Hillary Clinton in New Hampshire on Tuesday, CNN's John King reported on "Inside Politics" Sunday.

The Sanders campaign confirmed Monday that the Vermont senator will appear with Clinton at a Portsmouth High School rally. In a statement, the campaign does not use the term endorsement but bills the event as an opportunity "to discuss their commitment to building an America that is stronger together and an economy that works for everyone, not just those at the top."

The move comes after the Democratic Platform Committee, meeting in Orlando, adopted some of the Vermont senator's key positions.

Climate change, health care and a minimum wage hike are among the issues that the Sanders campaign are calling victories

However, some of Sanders' supporters are still critical of this upcoming endorsement, particularly over the party platform's language on trade.

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