WASHINGTON – An architect of anti-immigration efforts who says he is advising President-elect Donald Trump said the new administration could push ahead rapidly on construction of a U.S.-Mexico border wall without seeking immediate congressional approval.

Kansas Secretary of State Kris Kobach, who helped write tough immigration laws in Arizona and elsewhere, said in an interview that Trump’s policy advisers had also discussed drafting a proposal for his consideration to reinstate a registry for immigrants from Muslim countries.

Kobach, who media reports say is a key member of Trump’s transition team, said he had participated in regular conference calls with about a dozen Trump immigration advisers for the past two to three months.

Trump’s transition team did not respond to requests for confirmation of Kobach’s role. The president-elect has not committed to following any specific recommendations from advisory groups.

Trump, who scored an upset victory last week over Democrat Hillary Clinton, made building a wall on the U.S.-Mexico border a central issue of his campaign and has pledged to step up immigration enforcement against the country’s 11 million undocumented immigrants. He has also said he supports “extreme vetting” of Muslims entering the United States as a national security measure.

Kobach told Reuters last Friday that the immigration group had discussed drafting executive orders for the president-elect’s review “so that Trump and the Department of Homeland Security hit the ground running.”

To implement Trump’s call for “extreme vetting” of some Muslim immigrants, Kobach said the immigration policy group could recommend the reinstatement of a national registry of immigrants and visitors who enter the United States on visas from countries where extremist organizations are active.

Kobach helped design the program, known as the National Security Entry-Exit Registration System, while serving in Republican President George W. Bush’s Department of Justice after the Sept. 11, 2001, attacks on the United States by al Qaeda militants.

Under NSEERS, people from countries deemed “higher risk” were required to undergo interrogations and fingerprinting on entering the United States. Some non-citizen male U.S. residents over the age of 16 from countries with active militant threats were required to register in person at government offices and periodically check in.

NSEERS was abandoned in 2011 after it was deemed redundant by the Department of Homeland Security and criticized by civil rights groups for unfairly targeting immigrants from Muslim- majority nations.

Kobach said the immigration advisers were also looking at how the Homeland Security Department could move rapidly on border wall construction without approval from Congress by reappropriating existing funds in the current budget. He acknowledged “that future fiscal years will require additional appropriations.”

Congress, which is controlled by Trump’s fellow Republicans, could object to redirecting DHS funds designated for other purposes.

Kobach has worked with allies across the United States on drafting laws and pursuing legal actions to crack down on illegal immigration.

In 2010, he helped draft an Arizona law that required state and local officials to check the immigration status of individuals stopped by police. Parts of the law, which was fiercely opposed by Hispanic and civil rights groups, were struck down by the U.S. Supreme Court in 2011.

Kobach was also the architect of a 2013 Kansas law requiring voters to provide proof-of-citizenship documents, such as birth certificates or U.S. passports, when registering for the first time. A U.S. appeals court blocked that law after challenges from civil rights groups.

Kobach said in the interview he believed that illegal immigrants in some cases should be deported before a conviction if they have been charged with a violent crime. Trump said in an interview on CBS’ “60 Minutes” that aired on Sunday that once he took office, he would remove immigrants with criminal records who are in the country illegally.

Kobach said the immigration group had also discussed ways of overturning President Barack Obama’s 2012 executive action that has granted temporary deportation relief and work permits to more than 700,000 undocumented people or “dreamers” who came to the United States as children of illegal immigrants.