Prince Harry has met President Barack Obama for the first time during a flying visit to America to officially launch his Invictus Games.
The US leader greeted his royal guest in the White House's oval office after Harry had given an impassioned speech calling for military veterans to receive help, without being judged, for "invisible injuries" like post-traumatic stress.
Harry's comments came during a visit with Michelle Obama and Jill Biden, the wife of US vice-president Joe Biden, to a military centre providing care and rehab for wounded US veterans.
The trio's trip to the USO (United Service Organisations) Warrior and Family Centre at Fort Belvoir in Virginia highlighted the efforts by America to support their wounded veterans.
Speaking during the visit Harry said: "One thing we have to talk about more is breaking down these barriers around so-called invisible injuries, like post-traumatic stress, just as we have for physical injuries like the loss of a limb.''
Harry added: "People from all walks of life struggle with issues like post-traumatic stress, anxiety, and depression, not just veterans.
"We have to help them all to get the support they need, without fear of being judged or discriminated against.''
The prince's upcoming Invictus Games, a Paralympic-style championship for injured military personnel from across the globe, will be staged in Orlando, Florida, in 2016.
"It aims to challenge servicemen and women, many with serious injuries and disabilities, to strive for sporting excellence.
During his informal chat with Mr Obama that lasted around 30 minutes the two men discussed the Games.
In his speech delivered at the military base Harry also spoke about the profound effect fighting in Afghanistan has had on his life.
Harry said: "I am in no doubt that my two deployments to Afghanistan changed the direction of my life.
"There is very little that can truly prepare you for the reality of war. The experiences can be stark and long lasting.
"Returning to the UK after my first deployment, I shared the flight home with three critically injured British soldiers, all in induced comas, and the body of a Danish soldier, killed in action.
"It hit me then that this flight was one of many, carrying home men and women whose lives would be changed forever, and some who had made the ultimate sacrifice.
"From that moment, I knew I had a responsibility to help all veterans, who had made huge personal sacrifices for their countries, to lead healthy and dignified lives after service.''
During his tour of the USO Warrior and Family Centre with Mrs Obama and Mrs Biden, Harry sat down at a table and looked at artwork created by the veterans and they visited a music therapy room where wounded service personnel, their families and carers receive help.
The trio watched as keyboard player and singer Lieutenant Colonel Shane Tomko, a Marine, and drummer Sergeant Roderic Liggens played for their guests.
Harry, who was making a one-day trip to the US, listened patiently to the performance and at the end hugged the sergeant.
Later the prince, the first lady and Mrs Biden watched a wheelchair basketball match and when their royal guest first arrived in the sports hall Mrs Obama joked with the women in the stands saying: ''All right ladies, Prince Harry is here - don't pretend you didn't notice.''
Before their private meeting began Mr Obama, referring to Harry sitting close by, said: "He has gotten to know Michelle very well for a range of reasons but particular he's here to talk about the Invictus Games.
"An initiative that is bringing together wounded warriors from around the world under the leadership of Prince Harry and others, to make sure we see not simply the sacrifices they've made, but also the incredible contributions, strength and courage they continue to display."
In reply Harry thanked Mr Obama for hosting him, adding "especially in giving the Invictus Games the boost it so readily deserves, I suppose.
"We had huge amounts of fun designing the Invictus Games, based around stealing the Warrior Games off yourselves and making it international, making it better and now we're giving it back to you."