EU Home Affairs Commissioner Cecilia Malmström and US Attorney General Eric Holder are the driving forces of the initiative.
They jointly addressed the topic in an op-ed in the Dagens Nyheter (DN) newspaper on Tuesday.
Joint police investigations have resulted in the arrest of more than 300 people in the past two years, they wrote.
There are suspects in over 30 countries.
“The fact that child abusers seem to operate globally, disregarding national borders, is a reality that we must face,” Malmström and Holder wrote.
The alliance wants to find offenders and their victims, while also reducing the availability of child porn across the world.
A second aim is to raise public awareness of the risks children face when they are online.
Furthermore, the alliance states that it will ensure the assistance of child porn victims and provide them with support and protection.
“All efforts to monitor child pornography are of course good, and this initiative is really important,” National Bureau of Investigation (Rikskriminalen) inspector Björn Sellström told the TT news agency.
As child pornography is internet-based, cross-border cooperation is much needed, said Sellström.
“If we have a Swedish offender who gets in touch with a victim in Sweden but through American social media, then that site will ask us to get a court order before we can access information about the offender,” he said.
“It means it can take a really long time to investigate.”
The alliance also wants all countries to ban convicted sex offenders from working with children and teenagers.