Wunna Maung Lwi also promised that changes in Burma were “irreversible”.
But he later did not use the word political when referring to prisoners.
William Hague is the latest in a series of high-profile diplomats to seek to engage the new government in Burma and to try to bolster nascent signs of reform.
Western officials have been encouraged by recent changes, including legalising trade unions, lifting some media restrictions and a limited release of political prisoners.
But there are still grave concerns about Burma’s human rights record and the fact that several hundred political detainees remain behind bars.
“The foreign minister has reaffirmed commitments that have been made to release political prisoners,” he told reporters.
“He said the changes are irreversible and I welcome that way of thinking,” Mr Hague added.
“I stressed that the world will judge the government by its actions.”
But in an interview with the BBC Burmese service later, Wunna Maung Lwi said Burma did not acknowledge there were political prisoners.
They are all criminals, he said, and it was up to the president to decide when prisoners were released – adding that prisoners had already been freed on three recent occasions.