David Cameron arrived in Burma today in what is believed to be the first visit to the former colony by a British prime minister.
Upon his arrival the prime minister said Aung San Suu Kyi was "a shining example for people who yearn for freedom."
Speaking on the tarmac as he arrived in the new capital Naypyidaw, Mr Cameron said: "This country really matters. For decades it has suffered under a brutal dictatorship. It is also desperately poor. It doesn't have to be this way.
"There is a government now that says it is committed to reform, that has started to take steps, and I think it is right to encourage those steps."
During his historic visit, Mr Cameron is ready to signal the easing of sanctions against the country as he delivers a message of support to Nobel Peace Prize laureate Aung San Suu Kyi in person.
He is also due to meet President Thein Sein and congratulate him on pushing through democratic reforms.
At a joint press conference earlier in Mr Cameron's trip to south Asia, Malaysian prime minister Najib Tun Razak urged his counterpart to relax sanctions.
Mr Najib, who recently held talks with Mr Thein in Burma, said: "I really do believe first of all that he is sincere.
"This has been supported by Aung San Suu Kyi's own personal remarks about him."
He said sanctions should be eased quickly in order to shore up the president's popularity.
"We need to support a man like President Thein Sein so he will be supported by the community, because there will be elements who want to take a much more conservative approach," Mr Najib added.
Mr Cameron said developments in Burma may be "one potential chapter of light" in a "world where there are many dark chapters in history being written".
"Of course we should be sceptical. Of course we should be questioning. Of course we shouldn't be naive," he said.
But he added: "Aung San Suu Kyi herself, who has spent so many years in such a long, lonely but powerful struggle, believes that he is acting in good faith."
Britain had played a "leading role" in the imposition of sanctions, and would also not be "backwards" in responding to positive changes, he added.
Recent images of David Cameron in Indonesia