Kate, who has been suffering from Hyperemesis Gravidarum since September, is said to "very much hope" she can undertake the engagement, although the decision to attend will be reviewed if she is still unwell nearer the time.
The Duke and Duchess of Cambridge with President Tony Tan and his wife Mary in 2012
The Duke and Duchess are scheduled to take part in a ceremonial welcome for President Tony Tan Keng Yam and his wife Mary at the Royal Garden Hotel, which is a stone's throw from the couple's home at Kensington Palace.
It is not currently known if they will also take part in an official state banquet later in the evening.
William and Kate will represent the Queen at the ceremonial welcome
This will not be the first time that William and Kate have met the Singaporean leader.
In September 2012, the royal couple kicked off their Diamond Jubilee tour of Southeast Asia by attending a state dinner at The Istana – the president's official residence.
For the engagement two years ago, Kate showed off her finesse for diplomatic dressing by wearing a stylish print dress by Singapore-born designer Prabal Gurung. Royal fashion fans will be keen to see if she opts for one of the fashion house's vibrant prints once again.