Philadelphia - Donald Trump made his maiden voyage outside the Washington area as US president Thursday, meeting with lawmakers to map out their 2017 policy strategy and smooth emerging differences between the White House and congressional Republicans."This Congress is going to be the busiest Congress we've had in decades - maybe ever," Trump told hundreds of House and Senate Republicans at their winter retreat in Philadelphia.He spoke of booting "criminal aliens" from the United States, launching new one-to-one trade deals rather than sweeping regional pacts, bringing "justice" to American workers, and building a wall on the border with Mexico, an issue which triggered a row Thursday between the two nations.One of Trump's main messages was an assurance that he is committed to a longstanding and cherished Republican goal: dismantling his predecessor Barack Obama's health care reforms."Our legislative work starts with repealing and replacing Obamacare," Trump said to a cheer."We're actually going to sign the stuff that you're writing. You're not wasting your time."Trump's arguments over inauguration crowd size, his war of words with the media, and a revival of his claim of massive voter fraud has led to concerns within his own party that he is straying off message right from the start.But House Speaker Paul Ryan insisted there was little gap between his Republican caucus in the House and the new president."We are on the same page with the White House," Ryan told reporters, speaking about the Republican "timetable and legislative agenda" for the year.'Unconventional presidency' He acknowledged the unorthodox nature of the Trump presidency, but dismissed suggestions that the president's brash communication style was making Republicans bristle."This is going to be an unconventional presidency," Ryan said."I think we're going to see unconventional activities like tweets and things like that, and I think that's just something we're all going to have to get used to."For his part, Senate Majority Leader Mitch McConnell said he intended to "stick to the plan and make as much progress as we can."But he appeared to take a firm stand on Trump's declaration that torture "absolutely" works, and that the president will consider reintroducing enhanced interrogation techniques that have been widely condemned by Democrats and Republicans alike."I believe virtually all of my members are comfortable with the state of the law on that issue now," he said, referring to legislation that barred interrogation techniques like waterboarding.British Prime Minister Theresa May was to address the Republican gathering later Thursday, before traveling to Washington, where on Friday she will become the first foreign leader to meet Trump since he took office.'People are very upset' Several thousand protesters meanwhile converged on the streets of Philadelphia.As Trump arrived, people booed, chanted anti-Trump slogans, and held signs with messages like "Resist" and "Dissent is Patriotic."Lisa Gottschalk, an immunologist, said Trump will not be able to ignore the frustrations of Americans who see him rolling back Obama-era policies which they see as important."People are very upset," the 55-year-old told AFP. "He may not hear our message now, but come 2018, he will hear it," Gottschalk said, referring to mid-term elections.Joshua Roberts, a cancer patient on medical leave from his job at Drexel University, said he was protesting out of concern for Republican plans to repeal Obamacare, a move he said would hurt "millions" of Americans with pre-existing conditions.Roberts, 55, said he hoped Trump would stick to his goal of keeping the provision prohibiting insurance companies from declining coverage due to pre-existing conditions.But "I certainly don't trust the president much at all," he said.