President Donald Trump and British Prime Minister Theresa May sought to promote a unified front during a joint press conference Friday as Trump welcomed his first foreign leader to the White House since taking office.

The strength of the “special relationship” between the two countries came into question prior to the meeting as Trump championed policies opposed by May. But any divisions between the two leaders were downplayed as the president pledged to “renew our deep bond with Britain” and promised America’s “lasting support.”

May hoped to secure a bilateral trade agreement with the U.S. as Britain prepares to leave the European Union, a move supported by Trump but not her. She also sought assurances about America's commitment to NATO, which Trump has threatened to withdraw from. In her opening remarks, May said Trump assured her the U.S. is "100 percent behind NATO," though Trump did not utter the same assurances publicly.

Trump also announced during the press conference he would defer to his secretary of defense on torture. The president had signalled he wanted to return to the harsh interrogation techniques used under President George W. Bush, but Defense Secretary James Mattis’ commitment not to reinstate the interrogation practices would “override” his own support, Trump said.

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"He has stated publicly that he does not necessarily believe in torture or waterboarding, or however you want to define it — enhanced interrogation I guess would be a word that a lot of ... words that a lot of people would like to use,” Trump said. “I don't necessarily agree. But I would tell you that he will override because I'm giving him that power. He's an expert."

May’s visit comes at important junctures for both countries. World leaders have watched Trump's first week in office with unease as he made threats of a trade war with Mexico and promoted an "America first" agenda.

Trump said he had a “good” call with Mexican President Enrique Pena Nieto on Friday after he scrapped a trip to Washington scheduled for next week, but added that the countries would be “working on a fair relationship and a new relationship.”

May skirted around a question about whether the president’s actions made her uneasy, saying it was the business of the United States and Mexico.

Trump also plans to have a phone conversation with another world leader — Russian President Vladimir Putin — over the weekend. Trump told reporters it was "very early" to talk about lifting sanctions imposed by the Obama administration, which he has signalled a willingness to do. May said she strongly supports continuing the sanctions against Russia currently in place by the European Union.

Great Britain, too, finds itself in a moment of great uncertainty as it prepares to leave the European Union. May opposed the Brexit, which Trump supported, and is hoping for a strong show of support from the new president as Britain prepares to leave the E.U.

As part of that effort, May announced Trump had accepted an invitation from Queen Elizabeth II for a state visit later this year.

Though the leaders put on a unified front on Friday, May hinted at the areas of disagreement during an address to congressional Republicans at their retreat on Thursday.

She warned against the America's retreat from the world stage while also acknowledging Trump's calls to renegotiate U.S. responsibilities to international organizations.

May said organizations like the United Nations, World Bank and NATO are "are in need of reform and renewal" but maintained they said they have brought "peace and prosperity to billions of people."

The British leader also cautioned against cozying up to Russia, which Trump has continued to do after his election.

"When it comes to Russia, as so often it is wise to turn to the example of President Reagan who — during his negotiations with his opposite number Mikhail Gorbachev — used to abide by the adage 'trust but verify.' With President Putin, my advice is to 'engage but beware,'" May said.