Trump signs order targeting 'birth tourism'

US President Donald Trump on Thursday made another attempt to curb birthright citizenship, signing an order targeting those who he said enter the country under the guise of tourism while actually intending to give birth.

"They've taken birthright citizenship and they've made a joke out of it," Trump told journalists in the Oval Office.

The US Supreme Court struck down his previous effort to restrict the constitutionally granted right in a late June ruling that Trump described as "very unfortunate."

"We're making adjustments because it's very unfair," he said.

Stephen Miller, one of Trump's closest advisors, said the order also aims to deny birthright citizenship to others, including children of members of "foreign terrorist organizations" as well as "large categories of people who lobby and act on behalf of foreign governments."

The move "ensures that large numbers of people who wrongly (would) be getting birthright citizenship will no longer be eligible for those benefits," Miller said.

The president signed another executive order last year decreeing that children born to parents in the United States illegally or on temporary visas would not automatically become US citizens.

Lower courts blocked that move, ruling that under the Citizenship Clause of the 14th Amendment to the US Constitution, nearly everyone born on US soil is an American citizen.

The Supreme Court agreed in a majority opinion penned by Chief Justice John Roberts that was joined by two other conservative-leaning justices and the three liberal-leaning justices.

The 14th Amendment states: "All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States."

It does not apply to those not subject to US jurisdiction -- the children of foreign diplomats, for example -- and under US law, visas can already be denied if a consular officer believes the applicant is traveling to the country for the primary purpose of giving birth.

The Trump administration unsuccessfully argued that the 14th Amendment, passed in the wake of the 1861-1865 Civil War, addresses citizenship rights of former slaves and not the children of undocumented migrants or visitors.

Trump's previous executive order was premised on the notion that anyone in the United States illegally, or on a visa, is not "subject to the jurisdiction" of the country and therefore excluded from automatic citizenship.

The president's efforts to curb birthright citizenship are part of his wider campaign to limit immigration, which includes expelling millions of undocumented migrants and removing deportation protections from nationals of more than a dozen countries.