Boris Johnson has pledged to be there "in the long term" for British people whose Caribbean homes were ripped apart by Hurricane Irma.
Brushing aside critics, the Foreign Secretary said there had been an "unprecedented" relief effort from the UK and that he had "no doubt" Britain would meet the challenges ahead.
Irma has claimed at least 24 lives, including five in the British Virgin Islands and one each on Anguilla and Barbuda, and left thousands of people homeless when it smashed into the region on Wednesday.
It hit Florida over the weekend, bringing widespread flooding and leaving more than 3 million homes and businesses without power, and the category-three storm is now expected to tear up the state's west coast.
Mr Johnson said, in addition to the £32 million already set aside following the disaster, the Government would be matching public donations to the Red Cross appeal.
Returning from the latest in a series of emergency Cobra meetings, chaired by Defence Secretary Sir Michael Fallon, he said: "This is just the beginning.
"A terrible thing has happened to British overseas territories.
"These are British people and we are here for the long term and we will come through with a recovery plan working with our partners in the region.
"We will come through with a recovery plan for those islands and make sure they get back on their feet again."
More than 500 British troops are believed to be in the region, including 125 troops working with the local police on the British Virgin Islands, amid reports of looting.
The presence of the troops has had "a massive psychological effect" on morale on the islands, said Mr Johnson, adding that more than 50 British police were on their way to the region.
Three planes were on their way to deliver crucial supplies, he said, while the UK will be sending a military operation to Anguilla, one of the first islands to be hit by Irma and receive aid, as soon as possible to ensure it "does not now slip behind".
The Royal Navy ship RFA Mounts Bay, carrying engineers, marines and medics, delivered six tonnes of supplies to the British overseas territory and carried out repair work before moving on to the British Virgin Islands.
Mr Johnson said suggestions the UK response was not good or fast enough were "completely wrong".
He said: "Other countries actually now been asking us for help including the French, we've got three planes going out today, it's an unprecedented effort by the UK to meet what has been an unprecedented catastrophe in that part of the Caribbean.
"But I've absolutely no doubt that we can face up to the challenge, we can deliver the help that those islanders need, we are seeing some signs of improvement, things are getting better on BVI, we've now got to make sure Anguilla gets the help it needs."
Stephen Norris, commanding officer of RFA Mounts Bay, insisted his men were on the islands providing support as soon as the storm had calmed.
"Our reaction, I suggest, has been exemplary," he told BBC News.
"We were there as soon as we possibly could. Clearly, I don't wish to put my ship in danger and the 170 people on board."
