WASHINGTON, D.C.: Citizens from more than 30 countries could soon be banned from entering the United States, Homeland Security Secretary Kristi Noem said. The move follows a shooting in which a man from Afghanistan killed one National Guard member and wounded another.

This would enlarge on a travel ban first announced in June, which already blocks travel from 12 countries and limits entry from seven more. Earlier this week, Noem hinted online that additional countries would be included.

Speaking on Fox News with Laura Ingraham, Noem would not give details, saying President Donald Trump is still deciding which countries will be added.

After the recent shooting, the administration has already tightened restrictions on the 19 countries covered in the original ban, including Afghanistan, Somalia, Iran, and Haiti.

Ingraham asked if the list would grow to 32 countries. "I won't be specific on the number, but it's over 30," Noem replied. She argued that the U.S. should block travel from countries that are unstable or unable to verify their citizens' identities.

The Department of Homeland Security has not said when the updated ban will begin or which new countries are involved.

The Afghan suspect, Rahmanullah Lakanwal, has been charged with first-degree murder after Specialist Sarah Beckstrom died from her injuries on November 26. A second victim, Staff Sergeant Andrew Wolfe, remains in critical condition. Lakanwal has pleaded not guilty.

The Trump administration says stronger vetting is needed to keep the country safe. Critics argue the new actions unfairly harm people who have already passed strict screening.

In the past week, the administration has stopped asylum decisions, paused immigration processing for people from the 19 banned countries, and halted visas for Afghans who helped U.S. forces.

U.S. Citizenship and Immigration Services also said it will shorten the validity of work permits for refugees and asylum seekers, requiring more frequent renewals and security checks.

Countries believed tobe on the banned list include Afghanistan, Myanmar, Burundi, Chad, Cuba, Equatorial Guinea, Eritrea, Haiti, Iran, Laos, Libya, Republic of the Congo, Sierra Leone, Somalia, Sudan, Togo, Turkmenistan, Venezuela and Yemen.