In a letter sent to US Secretary of State Mike Pompeo on Monday, 39 members of Congress — led by Democrat Max Rose of New York — asked why white supremacist extremist groups are not included on the State Department’s list of Foreign Terrorist Organizations (FTOs).

The letter came a week after a neo-Nazi gunman killed two people outside a German synagogue.

“Today, if an American citizen swears allegiance to the Islamic State (or another Foreign Terrorist Organization on the list) and spreads their message of terror, there are several resources available to the Federal government to counter the threat,” the letter said. “However, if that same American citizen swears allegiance to a violent white supremacist extremist group based overseas and spreads their message of terror, the Federal government does not have access to the same tools.”

“As you know,” the letter continued, “the State Department’s criteria for inclusion on the FTO list are simple: be a foreign organization, engage in or retain the capability and intent to engage in terrorism, and threaten the security of US nationals or the national defense, foreign relations, or the economic interests of the United States. There are numerous examples of foreign white nationalist groups that fit these conditions. The American people deserve an explanation as to why these groups are not included on the FTO list.”

“Given that the threat picture has evolved substantially over the past 18 years since the September 11th attacks, and as we learn more about connections between certain overseas white supremacist groups and domestic terrorists, it is time we take the threat of violent white supremacist extremists more seriously,” the letter implored.