Actress Helena Bonham Carter and television presenter Natasha Kaplinsky have met Holocaust survivors in New York.
The pair are on a two-day visit to the US as part of Prime Minister David Cameron's Holocaust Commission, which was set up earlier this year.
Along with commission chair Mick Davis they hosted a tea party for 50 survivors of the atrocity at New York's Museum of Jewish Heritage.
Bonham Carter, whose grandfather Eduardo Propper de Callejon was posthumously recognised for his role in saving hundreds of Jews during the Second World War, said: " It has been an honour to meet so many Holocaust survivors today.
"Hearing their stories underlines the enormity of the task ahead of us as members of the Prime Minister's Holocaust Commission.
"We have a responsibility to keep these stories alive and a duty to ensure their memories will never be forgotten."
Kaplinsky described the trip as "highly informative" with "extraordinary access".
She added: "But the highlight has to be hearing the personal testimonies of these incredible Holocaust survivors.
"Like the hundreds of survivors I have met in the UK, these remarkable individuals work tirelessly to educate others by sharing their stories.
"We won't always have them with us. It is our duty to act now to keep their legacy alive and ensure the lessons of the Holocaust are not lost for future generations. "
They were due to meet Holocaust survivor and nobel peace prize winner Professor Elie Wiesel tonight.
Earlier, the delegation visited the newly opened 9/11 museum in New York.