International sanctions against Iran are the \"toughest ever\", US Secretary of State Hillary Clinton has said, adding that the US continues to believe there is time for diplomacy . Speaking at a joint press conference with Libyan Prime Minister Abdurrahim El-Keib, Clinton also stated that the international community is united in preventing Iran from obtaining nuclear capabilities. \"We are united in our concerns and condemnation of Iran’s actions that violate their international obligations, and we are united in continuing to press the Iranian regime to come to the diplomatic forum that the P-5+1 offers,\" media reports quoted the US top diplomat as saying. Clinton added that this unity has led to \"the toughest sanctions that the international community has ever imposed.\"