Majority Leader Harry Reid will bring a gun control bill to the Senate floor with expanded background checks on gun purchasers as part of the package.
Reid said he would on Thursday evening begin the process of bringing legislation to the floor for consideration in April.
"Later tonight, I will start the process of bringing a bill to reduce gun violence to the Senate floor. This bill will include the provisions on background checks, school safety and gun trafficking reported by the Judiciary Committee," Reid said.
Reid expressed hope that Sen. Charles Schumer (D-N.Y.), who is taking the lead on expanded background checks, will find a Republican co-sponsor before the Senate considers the legislation in April.
"I hope negotiations will continue over the upcoming break to reach a bipartisan compromise on background checks, and I am hopeful that they will succeed. If a compromise is reached, I am open to including it in the base bill," he said.
Senate Democratic aides describe the background-checks measure, which the Judiciary Committee passed by a party-line vote last week, as a placeholder. It would likely not receive 60 votes on the Senate floor.
Reid said the firearms bill must expand background checks.
"I want to be clear: In order to be effective, any bill that passes the Senate must include background checks," he said.
"The bill I advance tonight will serve as the basis for opening debate," he said. "Once debate begins, I will ensure that a ban on assault weapons, limits to high-capacity magazines, and mental health provisions receive votes, along with other amendments. In his State of the Union address, President Obama called for all of these provisions to receive votes, and I will ensure that they do."
On Tuesday, Reid warned that any measure that cannot muster 60 votes might not be included in the base bill scheduled for floor consideration.
Senate observers say there might not even be 40 votes for an assault weapons ban, and the expanded background check probably won't meet Reid's 60 vote threshhold. President Obama is not personally lobbying anyone yet - either Democrat or Republican - so it is an open question whether the Senate will pass anything significant regarding gun control in this Congress.