Trump moves to limit birthright citizenship weeks after Supreme Court setback

US President Donald Trump has renewed his effort to restrict birthright citizenship, just weeks after the Supreme Court blocked his earlier attempt to end the long-standing policy.

Trump signed two executive orders on Thursday aimed at limiting access to citizenship for some children born in the United States and cracking down on so-called birth tourism.

One of the orders broadens the categories of non-citizens whose children would not automatically qualify for US citizenship at birth. The other targets birth tourism, in which pregnant women travel to the United States to give birth so their children can obtain US citizenship.

Speaking from the Oval Office, Trump said the move was long overdue and criticised the Supreme Court for rejecting his previous attempt to overturn the policy, which has been in place for about 150 years.

"My Administration has guarded against the risks posed by malign foreign actors who attempt to swindle American citizens by taking advantage of the generosity of our Nation," Trump said in the first executive order.

Under the order, a child born in the US would not automatically receive citizenship if both parents are non-citizens and one of them belongs to a foreign terrorist organisation, works for a foreign government, has sought US citizenship through fraudulent means, or resides in a US territory where citizenship is not granted under federal law.

Citizenship for people born in US territories including Puerto Rico is established through federal legislation.

Trump and members of his administration have repeatedly criticised birth tourism, alleging that countries including Russia and China could exploit the practice to gain an advantage or facilitate infiltration of the United States.