According to the Technology Review, past efforts by USA scientists to use CRISPR have been inconsistent and resulted in "editing errors" that gave weight to arguments the technique "would be an unsafe way to create a person".
The effort to create genetically modified human embryos was carried out by Shoukhrat Mitalipov from the Oregon Health and Science University and involved changing the DNA of a large number of one-cell embryos, MIT Technology Review reported.
It is thought to be the first such work in the US; previous experiments like this have been reported from China.
The embryos were only allowed to develop for a few days, the report said.
Scientists wanted to show that they can eradicate or correct genes that cause inherited disease, like thalassemia.
The technology - described as like a genetic "cut and paste" is highly controversial because some observers fear that it could be used to create "designer babies", where parents would choose their characteristics.
Scientists have genetically engineered human embryos for the first time in the United States, according to a report in the MIT Technology Review.
"It's very hard to be able to comment on any specifics or the robustness of the science because there is no scientific paper", said Simon Waddington, Reader in Gene Transfer Technology at University College London.
Scientists familiar with the new USA work told MIT Technology Review that the OR team has improved these issues. However, Mitalipov said his team was able to avoid mosaicism by injecting CRISPR into the eggs at the same time they were fertilized with sperm. Until the numbers are published, it will not be clear to what extent this reduced mosaicism.
"It is proof of principle that it can work".
Last year, the Office of the Director of National Intelligence released a report that added genome editing to a list of weapons of mass destruction and proliferation, saying it "increases the risk of the creation of potentially harmful biological agents or products".
It involves technology called "CRISPR" to alter genes in embryos. However, if his research passes peer review it could be a significant step for scientists in the US. Along with the National Academy of Medicine, the academy stated that scientific advances make gene editing in human reproductive cells "a realistic possibility that deserves serious consideration".