WASHINGTON — The Biden administration wants Congress to provide $6.4 billion to pay for an initial U.S. response to Russia’s invasion of Ukraine, largely for military and humanitarian assistance in the region, three people familiar with the request said Friday.

The largest portions of money would be for the Defense and State departments and for the U.S. Agency for International Development, which distributes civilian foreign aid. Smaller amounts would be for the Treasury and Commerce departments, whose chief roles in the Ukraine crisis will be to apply sanctions against Russia, its financial institutions and state-owned businesses and its leaders, including President Vladimir Putin.

The request, which White House and other administration officials described to congressional aides in a conference call Friday, provides an early look at the costs American taxpayers could bear as a result of Russia’s attack on its western neighbor. Those assaults were in their second full day Friday as Russian forces pounded Kyiv, Ukraine’s capital.

The administration is seeking $2.9 billion for State Department, USAID and other programs for security assistance to Ukraine, Poland, the Baltic nations and other Eastern European allies, an administration official said. It would also cover food and other humanitarian assistance, energy and economic aid plus efforts to thwart Russian cyberattacks.

The administration official said there would also be $3.5 billion for the Defense Department but provided no detail. The sums could change based on events in Ukraine and the needs of allied countries, the people describing the phone call said.

All three people spoke on condition of anonymity because they were not authorized to discuss it publicly.

The $6.4 billion was less than the “well above $10 billion” figure that Sen. Chris Coons, D-Del., told reporters he expected earlier Friday. Coons, chairman of the Senate Appropriations subcommittee that controls foreign aid and State Department expenditures, had couched his figure by calling it “an initial guess.”

Coons had said he expected the administration request to cover the costs of helping millions of Ukrainian refugees who could flee to Poland and nearby NATO countries and supporting those nations’ armed forces.

He also seemed to suggest that U.S. aid to Ukraine could continue should it fall to Russian forces, saying there is “strong enthusiasm” for providing money to resupply, train and “whatever other covert and overt support is necessary and appropriate for the Ukrainian resistance.”

Coons said the money would also cover the expenses of monitoring and enforcing U.S. sanctions against Russia and for the Pentagon’s bills for deploying the 7,000 additional American troops that President Joe Biden has ordered be sent to Europe.

“I expect that there will be a supplemental request well above $10 billion,” Coons told reporters, calling it “an initial guess.”

Republican lawmakers would seem likely to strongly support money to help Ukraine and counter Russia, and Coons said he believed the request would get strong bipartisan backing. Spokespersons for leading Republicans did not immediately return requests for comment.

Coons spoke after returning from an extended trip to Germany, Poland and Lithuania, where he and other members of Congress discussed the crisis with European leaders.

Biden is expected to address the invasion during his State of the Union address to Congress on Tuesday.

Lawmakers, returning from a recess, plan to focus next week on writing bipartisan legislation financing federal agencies for the rest of this year. Leaders hope to approve that roughly $1.5 trillion measure by March 11, when money temporarily financing government will run out.

It was initially unclear whether the Ukraine money would be part of that broader budget legislation, if not how quickly it would move and whether lawmakers would attempt to attach additional U.S. sanctions against Russia.

Democrats are “looking at” including the Ukraine assistance and extra money for COVID-19 relief in the government-wide budget bill, said a congressional leadership aide who spoke on condition of anonymity because they were not authorized to discuss the process publicly.

Earlier this week, Rep. Barbara Lee, D-Calif., who chairs the House Appropriations subcommittee overseeing foreign aid, said the administration was expecting to need at least $1 billion for humanitarian assistance and another $1 billion in loan guarantees for economic support.

With lawmakers trying to wrap up budget work, administration officials have already informally told Congress that they’d like an additional $30 billion to combat the COVID-19 pandemic. That would include money for vaccines, testing and covering care for the uninsured.

That proposal has drawn strong opposition from the GOP and is expected to face an uphill climb to survive. Republicans say the administration should instead use unspent funds from multi-trillion COVID-19 relief measures already enacted.