Some Trump supporters (including Trump himself) claim that votes were counted in an unfair way. Has the US government done everything possible to prove that Biden is the legitimate winner of the election, such as recounts in all contested states? If not, why not, if it could restore peace? Is it that everything that reasonably could be done to prove that the count was done correctly, has already been done and these people are akin to conspiracy theorists who go buy a different set of logic?
Trump has been claiming the election would be fraudulent since at least April of last year. He also claimed that the 2016 election was fraudulent, even though he won. At no point has he or any of his supporters provided any evidence of the widespread fraud he has been claiming. Everything necessary to confirm the results has been done, but Trump refuses to accept the result and continues to spread misinformation and false claims of fraud. He is not interested in restoring peace, and has been actively stoking division and riling up his supporters.
At this point there really is no controversy about the election result (there never was a controversy other than that manufactured by Trump himself) and the fraud narrative is being pushed only by Trump and sycophantic Republicans and media outlets who seem to think this will benefit them by ingratiating themselves with Trump's base, who won't just go away once Biden is president.
Aside from all of that, it is not the US (Federal) Government's responsibility to carry out elections. That is the responsibility of the individual state governments, each of which have certified that the results are accurate (after recounts where necessary) according to their own laws and processes.