EU High Representative Catherine Ashton Tuesday expressed concern over the visit of President of Sudan, Omar Al-Bashir, to Nigeria, a State Party to the Rome Statute of the International Criminal Court (ICC). She recalled Al-Bashir is under an arrest warrant by the ICC for war crimes and crimes against humanity, her spokesman Michael Mann, said in a statement. She urges Nigeria to respect its obligations under international law to arrest and surrender those subject to an arrest warrant from the ICC, he said. The ICC is a valuable instrument enabling victims of violence or human rights abuses and their representatives, including States, to combat impunity for the most serious crimes, noted the statement. Genocide, crimes against humanity and war crimes must not go unpunished , it added.