Now Playing: Cautious optimism on Korean Peninsula

Now Playing: Trump and allies trade barbs at G7

Now Playing: Hurricane Bud about 200 miles off the coast of Mexico

Now Playing: Singaporean bars and restaurants cash in on Trump-Kim summit fever

Now Playing: Migrants rescue-ship left adrift as Italy-Malta standoff continues

Now Playing: Trump lashes out at Canada's Trudeau after G-7 summit

Now Playing: Singapore pub offers Trump, Kim cocktails

Now Playing: Final preparations on eve of historic Trump-Kim meeting

Now Playing: Tight security surrounds Kim Jong Un's hotel in Singapore

Now Playing: Original Trump Cap Cana buyer: 'We were betrayed'

Now Playing: See how North Korea is covering historic summit

Now Playing: Historic summit: Trump in Singapore

Now Playing: Trump responds to Trudeau's tariff threat

Now Playing: Countdown to historic summit with North Korea

Now Playing: 'Start Here' podcast: Trump's trade tiff

Now Playing: Inside Kim Jong Un's brutal regime in North Korea

Now Playing: Unprecedented security for Trump, Kim summit

Now Playing: Inside Kim Jong Un's strategy for Trump meeting

Now Playing: Trump clashes with America's G-7 allies

Now Playing: All eyes on Singapore summit to witness history