Prince Harry and Meghan Markle meet Sydney Invictus heroes

Prince Harry and Meghan Markle have joined the Australian Prime Minister at a London reception ahead of the Invictus Games in Sydney later this year.

Harry and his bride-to-be will meet servicemen and women from both Britain and Australia, some of whom have previously competed in the international sporting event.

The couple will also learn more about preparations for this year's games at the reception hosted by Malcolm Turnbull and his wife Lucy at Australia House on Saturday.

More than 500 competitors - made up of sick and injured military and veterans - from 18 nations are expected to compete at the Invictus Games in Sydney between October 20 and 27.

It is expected Harry, who is patron of the Invictus Games Foundation which oversees the delivery of the tournament, will travel to Australia for the event with Ms Markle, who will by then be his wife.

When Toronto hosted the Paralympic-style event last year the former Suits star, who at the time was living and working in the city, attended the opening and closing ceremonies and visited competitors with Harry.

The trip to Sydney is also likely to see the couple embark on their Commonwealth duties, meeting young Australians to discuss issues close to their hearts after Prince Harry was appointed youth ambassador.