The King has said he was "dreadfully saddened" to hear of the "devastating" earthquake in Colombia earlier this week.
In a joint statement with Queen Camilla released late on Tuesday, Charles, 77, sent his "deepest sympathy and heartfelt condolences" to the South American country.
Colombia experienced its strongest earthquake in the 21st century on Monday with a magnitude of 7.4. The number of people killed has risen to more than 250, according to local reporting.
Signing the personal message "Charles R.", the King wrote: "My wife and I were so dreadfully saddened to learn of the devastating earthquake that has struck your country, and the tragic loss of life and suffering it has caused.
© Getty Images"At this most difficult of times, our special thoughts are with the bereaved and injured, those awaiting news of family and friends and the emergency responders working tirelessly to support those in need."
The monarch added: "We greatly admire the resilience and strength of the Colombian people, and we send our deepest sympathy and heartfelt condolences during this most challenging and distressing period."
What has happened in Colombia?
The epicentre of the 7.4 magnitude quake was in the village of San José del Palmar, causing widespread destruction in western Colombia.
The quake was felt across Manizales, Cali, and Pereira, as well as neighbouring Ecuador and Panama.
© AFP via Getty ImagesIt struck shortly after 7.30am local time (1.30pm in the UK). More than 3,800 people are still missing, with searches for survivors continuing all day and through the night.
The Colombian government has declared a national disaster after meeting with the president, Abelardo de la Espriella.
The devastation comes less than two months after twin quakes devastated the north of Venezuela, killing more than 6,300 people.
Spanish and Monaco royals lead royal tributes
The King has now joined other royals, such as King Felipe and Queen Letizia of Spain, and Prince Albert and Princess Charlene of Monaco, in addressing the tragedy.
"Princess Charlene and I learned with deep emotion of the powerful earthquake that struck western Colombia yesterday, leaving many casualties and many injured," wrote Prince Albert.
© Getty Images"We wish to convey to the Colombian people our deepest solidarity and full support during these difficult times," a translated statement released by the Spanish Royal Household on 11 August read in response to the natural disaster.
It continued: "We offer our heartfelt condolences to those who have lost a loved one and to all those affected by the earthquake."
King Felipe had visited Colombia just days earlier for the inauguration of the new president, Abelardo de la Espriella, on 7 August.
