Chris Barrow

At the same time, campaigners delivering humanitarian aid have started arriving in Cuba as part of efforts to mitigate the effects of the blockade.

David Adler is lead organiser of the Convoy to Cuba.

One of the main issues, for example, is how electricity in its absence affects schools.

We're talking about a critical shutout from access to education, which is, of course, considered by the UN to be a fundamental right.

And a third, of course, is access to medicine.

So many of the delegates here have been visiting the hospitals where they're dropping their medicines and finding that the shelves are empty, that the criminal effects of this blockade are to deprive people of life-saving medicines.

And that's to say nothing of the consequences of the total blackouts, which affect people on pacemakers and dialysis, matters of life and death.

Our correspondent Will Grant, who's in Havana, told Will Chalk more about the aid convoy.

It's called the Nuestra America convoy, named after an essay by the Cuban poet and independence hero José Martí.

But it has run into difficult weather.

It's been a difficult few days in terms of the weather and the sea conditions around Cuba the past week.

So as far as we know, the authorities have simply said it's suspended for now, but it will be making it to the island eventually.

And I mean, from the outside, it's quite hard to imagine what everyday life is like.

You are in Havana.

Can you shed some light for us?

Well, I mean, obviously, this convoy is bringing with it 20 tonnes of things, including solar panels, emergency food packs, medicines and things, which will be welcomed.

But I think the main thing that it brings that matters to people is a sense of solidarity that they're not on their own.

And that is welcome, too.

But, of course, 20 tonnes is nothing compared to the need on the island.

What people need are huge amounts of emergency aid.