WASHINGTON -- President Joe Biden will meet separately with moderate Democratic senators Joe Manchin and Kyrsten Sinema on Wednesday to discuss Democratic-backed domestic spending legislation, sources familiar with the meetings said.

The Democrats hold a slim majority in the Senate, making Manchin and Sinema critical to the legislation's prospects.

Sinema represents Arizona and Manchin, West Virginia.

The legislation -- opposed by Republicans -- aims to supplement a separate bipartisan $1 trillion infrastructure bill and would focus on education, child care, climate-related projects and other matters.

The meeting comes after Manchin over the weekend said he would not back a $3.5 trillion package and urged a slimmer version, putting him at odds with other Democrats backing the larger bill to tackle the party's major policy goals while they maintain a narrow hold on Congress.