Announcement comes after Washington criticises Tuesday's boycotted presidential poll and calls for "mediation process".
The US will review its relations and level of aid to Burundi over the next two months after the central African nation held a disputed presidential election earlier this week, the US ambassador to the country has said.
The US provides training and equipment worth about $80m a year for Burundi's military and security forces, along with other aid, supporting a nation now in crisis after President Pierre Nkurunziza ran for a third term on Tuesday.
Critics say seeking a third term was inconstitutional but Nkurunziza, who cited a court ruling saying he could run, is expected to be announced as the winner on Friday after an opposition boycott of the vote.
"Over the next couple of months we will be reviewing very carefully the level of our assistance, what programmes will be continued or not," Ambassador Dawn Liberi told the Reuters news agency on Thursday, adding it would be driven by policy concerns and administrative issues.
"It is a process that will obviously continue depending on what happens politically," she said, calling for steps to ensure full democratic freedoms, disarming militias and lifting curbs on the media after private radio stations were shut down.
"What we are calling for is for all parties to go back to the mediation process and try to forge a way forward that is inclusive," she said. The aim, she added, is to ensure US aid to the health, and other such, sectors is not affected.
Opponents say Nkurunziza violated the constitution by running in Tuesday's race.
The US and other donors had urged the president to stick to the two-term limit laid down in a peace deal that ended civil war in 2005.
'We prefer our dignity'
Weeks of protests in which demonstrators clashed with police preceded the June 29 parliamentary election, while explosions and gunfire erupted in Bujumbura before the presidential vote.
The government says the elections were fair and accuses the opposition of stoking tensions. Burundi, which relies on aid to fund half its budget, says it wants good ties with donors but will not let them dictate policies.
"We prefer our dignity, not people to come to impose their law and their point of view in our country," presidential adviser Willy Nyamitwe told Reuters.
Some US aid has already been halted or disrupted, in part because some US personnel were pulled out of Burundi due to the unrest.
Washington's support includes training Burundi troops serving with an African Union force in Somalia.
The US has also imposed visa bans on some Burundian government officials, while not naming them.
European Union states have halted some aid and threatened further punitive steps.