House and Senate Republican leaders are pressuring reluctant Democrats to accept a deal to temporarily fund the government in the fight against Zika, promising to include aide for Flint, Mich., in a separate measure.

Senate Democrats said they oppose a deal that would keep the government funded until Dec. 9 and provide $1.1 billion to combat the mosquito-transmitted Zika virus. Party lawmakers are insisting the legislation also include more than $200 million to help Flint deal with a lead-contaminated water supply.