European Union foreign ministers have agreed not to renew the union's arms embargo on the Syrian opposition.
But there was "no immediate decision to send arms" to Syrian rebels and all other sanctions remained in force, the UK Foreign Secretary William Hague said in a tweet.
The decision came after lengthy talks in Brussels.
A far-reaching package of sanctions against the government of Bashar al-Assad was due to expire on 1 June.
Britain and France had been pressing to send weapons to what they call moderate opponents of President Assad.
But other countries had opposed the move, saying it would only worsen the violence.