Now Playing: Debate over 'zero-tolerance' policy intensifies

Now Playing: Crisis at the border

Now Playing: Debate over Trump administration's 'zero-tolerance' policy heats up

Now Playing: US withdraws from UN Human Rights Council

Now Playing: Comey doesn't agree with IG report but respects the criticism

Now Playing: All GOP senators want to halt separation of families at border, McConnell says

Now Playing: President Trump digs in on false claim that crime on rise in Germany

Now Playing: Trump launches into free-wheeling defense of 'zero tolerance policy'

Now Playing: Lawmakers turned away from migrant detention center

Now Playing: DHS Secretary Kirstjen Nielsen says separating kids at border isn't abuse

Now Playing: Rev. Al Sharpton decries separation of immigrant families

Now Playing: Senators refute Trump's stance that only Congress can end child separation at border

Now Playing: Congressman blasts immigration policy, makes emotional plea to GOP

Now Playing: Trump to meet with Republican lawmakers on immigration

Now Playing: Justice Department IG investigating Comey memos after FBI referral

Now Playing: President Trump doubles down on immigration amid backlash

Now Playing: Nielsen defends family separation as enforcing the law: 'We will not apologize'

Now Playing: Trump directs creation of 'space force' as sixth branch of military

Now Playing: Trump: 'The US will not be a migrant camp'

Now Playing: Trump blames Democrats for border policy separating children from parents