Media playback is unsupported on your device Media caption The Duke and Duchess viewed an orchid named after William's mother, Diana

The Duke and Duchess of Cambridge have been formally welcomed to Singapore on the first day of their tour of South East Asia and the South Pacific.

Prince William was accompanied by President Tony Tan to inspect a guard of honour at the presidential palace.

Earlier, the couple viewed an orchid named after the duke's late mother, which she never had a chance to see.

The prince, at a state dinner, also praised the commitment and fortitude of the Queen.

'Exceptional dedication'

In a short speech at the official residence of President Tan, Prince William paid tribute to his grandmother, saying the Diamond Jubilee had been "a celebration of the Queen's exceptional dedication over 60 years".

He added: "Her service has not just been to the peoples of her realms, but to the whole Commonwealth family, of which Singapore is such an important member."

Analysis In their second year of marriage, William and Kate are undertaking their second major overseas tour. They will visit two former British colonies on behalf of the government and two realms on behalf of Prince William's grandmother. As things stand, in years to come, the tiny South Pacific islands will welcome the couple as their king and queen. For now, the islanders have more pressing matters to attend to. The inhabitants of Tuvalu fear it could be swamped by rising sea levels. The residents of the Solomon Islands are recovering from a civil conflict that brought it to the brink of collapse. During the tour, these past troubles and current concerns will be on display. So too will be the future of the British monarchy, as the couple travel to four countries over nine days to celebrate the Queen's Diamond Jubilee. In pictures: Royal visit day one

The duke also thanked Singapore for being "very much part of our Olympic story", the Games having been awarded to London in 2005 at a press conference in Singapore.

Earlier, William and Catherine visited Singapore's Botanic Gardens' to view an orchid named after the duke's mother Diana, Princess of Wales.

Alan Tan Chye Soon, manager at the garden, said it was "so sad" the princess did not get chance to see the bloom, but added: "It was like William and Kate are fulfilling her promise today."

The princess died in a car crash in August 1997 just weeks before she was due to visit the gardens to see the orchid.

William and Catherine also saw a pink orchid - Vanda William Catherine - named after themselves.

Media playback is unsupported on your device Media caption Prince William made a speech at the state dinner which praised the Queen

'Global superstars'

The royals were greeted on Tuesday morning at Singapore Changi airport by senior parliamentary secretary for the ministry of defence, Maliki Osman, who said it was a "great honour" to have the couple in Singapore.

Antony Phillipson, British high commissioner to Singapore, who also greeted the couple, said there had been "mounting excitement" about the visit.

"This is a couple who are global superstars and make the British feel very, very good about themselves - that's as true in Singapore as anywhere else."

The royal couple will also visit Malaysia, the Solomon Islands and Tuvalu during the trip to mark the Diamond Jubilee.

The duchess will also make her first speech in a foreign country when she addresses staff and patients at a Malaysian hospice.

Correction 14 September 2012: This report has been amended to replace a quote by President Tan which had inadvertently been attributed to Prince William.