Three House Republicans demanded Homeland Security Secretary Jeh Johnson formally denounce the Muslim Brotherhood, according to a letter released Wednesday evening.

Reps. Steve King of Iowa, Louie Gohmert of Texas and Randy Weber of Texas said Johnson is legitimizing the terrorist group.

"It is appalling to know that the secretary of Homeland Security for the Unites States, Jeh Johnson, appeared last Sunday before the Islamic Society of North America (ISNA), the largest Muslim Brotherhood front in our country today," King said. "The brotherhood has been more than vocal about their intent in America: 'destroying Western Civilization from within.' Furthermore, ISNA has been identified as the first of 29 groups the brotherhood has openly referred to as 'our organizations and organizations of our friends.'

"It is astounding that the individual principally charged with defending the homeland would legitimize, let alone pander to, an organization or its proxy that poses a threat to our constitutional republic and its people.

"The fact that you have explicitly called for your appearance before ISNA to serve as a precedent for other Cabinet officials to do the same amounts not just to willful blindness about the nature of the enemy. It is malfeasance," the letter continued.

The three congressmen also argued in favor of the Muslim Brotherhood Terrorist Designation Act of 2015, which was supported by 64 bipartisan cosponsors.