US State Department spokesperson Edward Price says the country has "no higher priority than the safety and security of American citizens around the world".

He was speaking at a press briefing late on Friday after the US, in the space of two days last week, issued security threat alerts in Nigeria and South Africa. No details about the security threats were provided.

The move was met with mixed feelings in both countries and in SA, it almost amounted to a diplomatic tiff.

But Price said the US acts on information to mitigate threats.

"We also have a responsibility to the American citizen community around the world that we provide them with timely notification when we have information available to us regarding a potential threat. 

He added, "So, in that vein, when we are in possession of information regarding a potential threat, we do provide it to American personnel. We take steps – prudent steps - to mitigate the threat, but also to inform the public."

In Israel, a US ally advised its nationals to avoid travelling to Nigeria.

Following the alerts, Nigeria and SA deployed more security personnel in suspected areas. SA tightened security at weekend public gatherings and in Nigeria, families of embassy employees were told to depart. 

However, there are concerns that the US didn't follow due process by liaising with local authorities before issuing the alerts, particularly in SA.

SA President Cyril Ramaphosa condemned the US for issuing the security threat statement without consulting his government. 

"Any form of alert will come from the government of the Republic of South Africa and it is unfortunate that another government should issue such a threat [and] send panic amongst our people," Ramaphosa said.

Price insisted that the US values its partners in the fight against terrorism.

"We do cooperate closely with countries around the world – certainly, close partners like South Africa, like Nigeria – on shared security concerns," he said.

He added that he understands that SA was deeply concerned about protecting its interests.

"We have a close relationship with our South African partners, and we deeply appreciate efforts that they make to protect their interests, and in turn, our interests in the country as well."