Syrian President Bashar al-Assad accused Britain of wanting to arm rebels fighting to oust his government, in a rare interview published by a London-based newspaper Sunday, dpa reported.
"How can we expect to ask Britain to play a role while it's determined to militarize the problem?" al-Assad told The Sunday Times newspaper.
"How can you ask them to play a role in making the situation better, more stable, how can we expect them to make the violence less when they want to send the military supply to the terrorist?"
The government of David Cameron could not play a "constructive" role in ending the conflict, he said.
Damascus refers to Syrians who took up arms against it almost two years ago as "terrorists." The conflict has claimed an estimated 70,000 lives.
Britain has repeatedly called for al-Assad to step down and is lobbying for the European Union's embargo on arms supplies to rebels in Syria to be lifted.
The bloc last week extended the embargo, part of its sanctions against Syria, for a further three months.
"The Syrians are the only ones who can tell the president to stay or to leave," the Syrian leader told The Sunday Times.
The interview conducted last week was al-Assad's first with Western media in more than a year.