REUTERS/Mark Makela
The UK Prime Minister told the annual Congressional Republican Retreat in Philadelphia that the two countries must take a "lead" role in global
This particular section of May's speech was hugely significant as it pointed to an unravelling of the "liberal interventionist" foreign policy consensus championed by Tony Blair.
Liberal interventionism is the belief that powerful western democracies like the US and US should take an active role in spreading democratic values across the globe, and led the nations to undertake a contentious military intervention in Iraq following the 9/11 terrorist attacks.
In her speech, which you can read in full here, May said:
"So we - our two countries together - have a responsibility to lead. Because when others step up as we step back, it is bad for America, for Britain and the world.
"It is in our interests - those of Britain and America together - to stand strong together to defend our values, our interests and the very ideas in which we believe.
"This cannot mean a return to the failed policies of the past. The days of Britain and America intervening in sovereign countries in an attempt to remake the world in our own image are over. But nor can we afford to stand idly by when the threat is real and when it is in our own interests to intervene. We must be strong, smart and hard-headed. And we must demonstrate the resolve necessary to stand up for our interests."
May used her first address to the President to announce support for many of his foreign policy positions.
The Conservative Party leader condemned the "malign influence" of Iran, vowed to "stand up" for Israel and said she would assist Trump in defeating the Islamic State terrorist group.
However, May urged the President to be cautious when dealing with Russian President Vladimir Putin, saying the US should "engage but beware" Russia, and encouraged him to embrace NATO as a "vital" international organ.
The UK prime minister described Trump's campaign rhetoric as "divisive, stupid and wrong" in the run-up to the US election. Yet, in Philadelphia, she praised the President's victory as being rooted in the "hopes and aspirations of working men and women" across the US and said that under his leadership the country would undergo renewal.
May paid tribute to the "special relationship" between the UK and US as a coalition that has "defined the modern world" and invited Trump to join her in taking a lead role in shaping global politics. She said:
"So as we rediscover our confidence together - as you renew your nation just as we renew ours - we have the opportunity - indeed the responsibility - to renew the Special Relationship for this new age. We have the opportunity to lead, together, again.
"I believe it is in our national interest to do so. Because the world is increasingly marked by instability and threats that risk undermining our way of life and the very things that we hold dear."
May and Trump will hold a joint press conference at around 6.00 p.m. GMT (1.00 p.m. ET).