The two-year-old son of a Yemeni woman who sued the Trump administration to let her into the United States to be with the ailing boy has died.

The Council on American-Islamic Relations announced that Abdullah Hassan had died at a children's hospital in Oakland, California, where his father Ali Hassan had taken him in the autumn for treatment for a genetic brain disorder.

The boy and his father are American citizens, but his mother Shaima Swileh is not so she remained at their home in Egypt while fighting for a visa.

Yemeni citizens are restricted from entering the US under President Donald Trump's travel ban.