The United States and Britain have the responsibility to renew their "special relationship" for a new era and could "lead together" again, British Prime Minister Theresa May said Thursday. May spoke to a gathering of Republican members of Congress in Philadelphia ahead of her first face-to-face meeting with US President Donald Trump on Friday. "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," May said. The world is "passing through a period of change," and in response the two countries can either be passive bystanders "or we can take the opportunity once more to lead and to lead together," she said. The British prime minister, who will be the first world leader to meet the newly inaugurated president, said she was "delighted" that a trade agreement between Britain and the United States was one of Trump's early priorities. Such a deal could demonstrate to people who feel "locked out and left behind" by globalization that free markets and free trade can deliver better jobs and security. Britain is seeking a bilateral deal with the US following its decision to leave the European Union in June. But May also expressed foreign policy positions that differed from those taken by Trump on the campaign trail. She said the West should be wary of Russia and consider taking the "trust but verify" approach espoused by president Ronald Reagan. She also described the Iran nuclear deal as "vitally important for regional security," while Trump threatened to tear it up. May also said institutions Trump has denigrated like the United Nations and NATO were important, but said they were "in need of reform and renewal to make them relevant today." She added that while "newly emboldened, confident America is good for the world," it should not have to lead alone, particularly in the area of defence. "You have said that it is time for others to step up, and I agree," May said. "Sovereign countries cannot outsource their security and prosperity to America." Britain is the only other country in the G-20 that meets its commitment to spend 2 per cent of GDP on defence and to invest 20 per cent of that in upgrading equipment. May has been pressured to take Trump to task over comments he made in support of torture. British opposition leader Jeremy Corbyn called on May to condemn Trump's remark that he had absolute faith that waterboarding "works." "When you meet Donald Trump, you must put our values, not America first. Say no to waterboarding. It's torture," the Labour party leader tweeted on Thursday. May had already been grilled by parliament on Wednesday, before Trump made the comments, on how she would approach the new president on issues such as torture and climate change. She told British lawmakers "we do not sanction torture" and reiterated that she was "not afraid to speak frankly" to the president, but would not confirm whether the use of torture would be on the agenda for the meeting.