Washington (CNN) Rob Joyce, President Donald Trump's former cybersecurity coordinator, has been tapped to serve as the National Security Agency's top representative in the United Kingdom, according to a former senior intelligence official and a second source familiar with the matter.

As senior US liaison officer in London for the US's top digital spy agency, which vacuums up communications from around the globe, Joyce "will be responsible for the full breadth of NSA mission in and to the UK government," the former senior intelligence official told CNN.

It is "the most important overseas post the NSA has," they added, due to the NSA's close relationship with the British digital intelligence agency, the Government Communications Headquarters or GCHQ.

Joyce's appointment, following a stream of high-level White House departures after John Bolton took the reins at the National Security Council, comes at a time when Trump's negative comments about trade, defense spending, intelligence and other topics in Brussels and Helsinki sent a shockwave through Europe and around the world.

Since Trump became President, former and current intelligence officials have routinely said that working relationships with counterparts overseas remain strong and unimpacted by political chaos.

Read More