Trump signed two executive orders, a written order issued by a president to the federal government which does not require congressional approval, on Thursday.

One expands the existing definitions of non-citizens whose children are not eligible for birthright citizenship.

It prevents the automatic citizenship of babies born in the US to two non-citizen parents if one of the parents is a member of a foreign terrorist group, is a foreign government employee, has attempted to gain citizenship through fraudulent means, or is living in US territories where citizenship is not granted by US federal law.

A few of those categories were already excluded under current birthright citizenship rules, but the one relating to membership of a foreign terrorist group could raise issues, according to Colleen Putzel-Kavanaugh, an associate policy analyst at the Migration Policy Institute, an independent nonpartisan research group.

She said it is difficult to know how, when, and by whom membership would be determined, and it is also not clear “if the onus for proof falls on the government (to prove they are a member) or the individual (to prove they are not)”.

The second order, meanwhile, seeks to end the practice of birth tourism by directing the departments of state and homeland security to enhance regulations and expand enforcement against the practice.

It is already illegal to travel to the US for the purpose of giving birth.

According to the executive order, operators in the birth tourism industry use deceptive advertising to entice foreign nationals to give birth in the US.

“They promise citizenship; access to public benefits; and short-term stays in specialised facilities, hotels, or rentals, but often fail to deliver on these promises,” the order says.