This is the Global News podcast from the BBC World Service.

I'm Nick Miles, and in the early hours of Saturday the 2nd of August, these are our main

stories. President Trump has told the US military to reposition two nuclear submarines in response

to what he called foolish and inflammatory comments by Russia's former leader, Dimitri Medvedev.

Mr. Trump has ordered the sacking of the head of the U.S. Bureau of Labor Statistics,

after it published disappointing job figures.

Reports from northern Burkina Faso say attacks by jihadists have left dozens of people dead,

including soldiers and civilians.

Also in this podcast.

From a biological perspective, there's no limit.

So once the embryos are frozen, all cellular activity stops.

They're stored in a sort of a suspended animation state.

We hear about what some are calling the world's oldest baby from an embryo

that was frozen 30 years ago.

We begin in the United States. President Trump has responded to strident comments by the former

Russian president, Dimitri Medvedev,

by saying that he will reposition two U.S. nuclear submarines in what he called appropriate regions.

But Mr. Trump did not say if he was referring to nuclear-powered or nuclear-armed submarines,

or what regions he was talking about.

We just have to be careful.

And a threat was made, and we didn't think it was appropriate.

So I have to be very careful.

...