President Barack Obama told guest attending a reception at the Nato Wales summit that he will encourage people in the United States to visit Wales.
Obama is the first serving US president to visit Wales.
According to the BBC, he praised the country's "extraordinary beauty, wonderful people and great hospitality" while speaking at an event hosted by the Prince of Wales to thank the local people involved in organising the summit.
Earlier in the day Barack Obama and David Cameron visited a primary school in Newport.
Mr Obama's car was adorned with an American and Welsh flag, and he greeted the smiling youngsters of Mount Pleasant Primary School in Welsh saying "bore da" which means "good morning", reports Wales Online.
Pupils at the school are among the youngsters across Wales who have written postcards to leaders attending the summit, telling them what they would like to see changed in the world by the time they are adults.
Their messages will be presented to Nato leaders at the summit.