Facing what President Barack Obama has called a new phase of terrorism, US officials are appealing to Muslim Americans to fight harder against extremist ideology.
The Obama administration has defended Muslim Americans after attacks in Paris and San Bernardino, California, and the inflammatory rhetoric that came in its wake, while a parallel message to Islamic communities is gaining urgency: please help.
As Republican presidential candidate Donald Trump suggested banning all Muslims from entering the country on Monday, Homeland Security Secretary Jeh Johnson stood in solidarity with an imam and leaders of other faiths at a northern Virginia Islamic centre.
Johnson would not comment on Trump's remarks but urged Americans not to vilify Muslims or throw a "net of suspicion" over an entire community.
But he had also made another appeal, this one to Muslim communities.
"Terrorist organisations overseas have targeted your communities. They seek to pull your youth into the pit of violent extremism. Help us to help you stop this," he said.
Since the deadly November 13 attacks by Islamic State followers in Paris and last week's California shootings, there has been a clear call from American officials for Muslims to help police themselves.
Three days after the Paris attacks, Obama urged Muslims around the world to ask "very serious questions" about how extremist ideologies take root and protect children from the idea that killing can be justified by religion.
"To some degree, that is something that has to come from within the Muslim community itself," Obama said at a news conference in Antalya, Turkey, after the G20 summit.
"I think there have been times where there has not been enough pushback against extremism."
The president made a similar plea in Sunday's Oval Office address on counterterrorism efforts. White House spokesman Josh Earnest on Monday said Muslims will have to speak out against radicalising forces in their own community.
"We would like to see leaders in the Muslim community stand up and speak out more forcefully in terms of condemning these hateful, radicalising messages that we see from extremist organisations," Earnest said at a news briefing.
Leaders of the Islamic centre where Johnson spoke, All Dulles Area Muslim Society, say they've been doing all they can since the September 11, 2001, al Qaeda attacks on New York and Washington.
"There's more denunciations coming from the Muslim community - not just now but for 14 years. Mosques are speaking out left and right," said Rizwan Jaka, a trustee of the Virginia centre.
The centre has been working with local and federal law enforcement and created think tanks and nonprofit organisations dedicated to counter-radicalisation, he said.
But people who get radicalised tend to go to mosques or be involved in their communities, which makes them harder to spot, he said.
