HER 5000 strong crew call her the 'big stick' - and she's sitting right on our doorstep.

Whopping American aircraft carrier USS Theodore Roosevelt dropped anchor in the Solent yesterday afternoon.

She will remain here until Friday, a potent reminder of our NATO ally's maritime might.

The 100,000 tonne vessel is on her way to take over the war against ISIS from fellow carrier USS Charles Vinson.

On board her are around 60 F18 fast jets - a total that's more than many countries own.

These will be used to launch bombing raids on ISIS from far out at sea.

The USS Theodore Roosevelt sailed east from her base in Norfolk, Virginia, with her carrier strike group which includes three other major warships and a total of 9000 sailors and US Marines.

Amongst them is the destroyer USS Winston S. Churchill which, because she's named after British Prime Minister, always carries a member of the Royal Navy in her ships company.

The current holder of the post is Lieutenant Lynsey Sewell.

The timing of the five billion dollar vessel visit has not been lost on military experts.

It comes as the debate still rages as to whether Britain should pledge to spend two per cent of GDP on defence - an issue on which David Cameron appeared to be wavering.

Commenting on the visit, the Royal Navy First Sealord Admiral Sir George Zambellas said: “It is excellent to see US navy carrier steel in Portsmouth.

“And in barely two years we will see UK carrier steel here too.

“We warmly welcome the Theodore Roosevelt Carrier Strike Group - a reflection of the close partnership between our nations and navies, and the value of credible sea power in support of our shared national interests.”

The first of Britain's new carriers HMS Queen Elizabeth is set to arrive at Portsmouth Naval Base in two years time.

The 55,000 tonne vessel will later be joined by sister ship the Prince of Wales as part of the Royal Navy's work up to the restoration of British carrier strike are future F35 pilots are currently training with the US Navy and deploying on some of their 18 carriers.

Among them is Lieutenant commander Stephen Collins, the first non-American to successfully complete the elite Top Gun course, on which the iconic film starring Tom Cruise and Val Kilmer was based.