The British prime minister says the United Kingdom and the United States must not intervene in other sovereign countries’ affairs in an attempt to “remake the world in our own image.”
Theresa May told a meeting of Republican lawmakers in Philadelphia, Pennsylvania, on Thursday that the "days of Britain and America intervening in sovereign countries in an attempt to remake the world in our own image are over.”
However, she insisted that the two powers should still lead the world and take on "new global challenges,” including the Syrian crisis and the fight against the Daesh (ISIL) terrorist group.
"This cannot mean a return to the failed policies of the past. But nor can we afford to stand idly by when the threat is real and when it is in our own interests to intervene,” she said.
"We must be strong, smart and hard-headed. And we must demonstrate the resolve necessary to stand up for our interests,” she added.
The British premier congratulated the Republican Party on its election victories in November, particularly Donald Trump’s triumph in the presidential election, saying it came in defiance of "pundits and polls."
"Because of this, because of what you have done together, because of that great victory you have won, America can be stronger, greater, and more confident in the years ahead," she said.
"And a newly emboldened, confident America is good for the world,” May argued.
She received a standing ovation when she pledged her commitment to the "special relationship" between London and Washington.
May told Republicans that like them she is also a conservative and believes in transferring power to the people, wooing GOP lawmakers ahead of her meeting with President Trump on Friday at the White House.
She will become the first foreign leader to meet with the US president following his inauguration last week.
Elsewhere in her speech, May urged the Trump administration to engage with Moscow but "beware" of Russian President Vladimir Putin.
"When it comes to Russia, as so often it is wise to turn to the example of President (Ronald) Reagan who -- during negotiations with his opposite number Mikhail Gorbachev -- used to abide by the adage 'trust but verify,’” she said.
"With President Putin, my advice is to 'engage but beware,'" the UK prime minister told US Republican lawmakers.
Trump has said on many occasions that he would push for warmer relations with Moscow.
He indicated in recent interview with The Wall Street Journal that he might even remove US sanctions against Moscow and consider a meeting with his Russian
Echoing some of Trump's concerns about NATO, May said the US-led military alliance must be reformed and also other international institutions such as the United Nations.
She said the allies of the US and UK "should not undermine the alliances that keep us strong by failing to step up and play their part."
"But those multinational institutions need to work for the countries that formed them, and to serve the needs and interests of the people of those nations. They have no democratic mandate of their own," she said.
In an interview prior to the US visit, the British premier said she was sure that Trump "recognizes the importance and significance of NATO.”
"I’m also confident the USA will recognize the importance of the co-operation we have in Europe to ensure our collective defense and collective security," she added.
In a recent interview with two European newspapers, Trump said NATO was "obsolete, because it was designed many, many years ago” and that "because it wasn't taking care of terror.”
European nations have said they are "astonished” by Trump’s comments about NATO, which has been a cornerstone of Europe’s defense policy since the end of World War II.