The NUP leader Al-Sadiq al-Mahdi on Thursday returned to the Sudanese capital Khartoum from his 30-month self-exile in Egypt. (AFP photo)

KHARTOUM, Jan. 26 (Xinhua) -- Leader of Sudan's opposition National Umma Party (NUP) Al-Sadiq al-Mahdi on Thursday vowed to stop the war and achieve peace and democratic transformation in Sudan.

Al-Mahdi said when addressing hundreds of his supporters at Omdurman city that he has returned to achieve specific goals represented in stopping the war and achieving peace and democratic transformation.

Al-Mahdi urged the Sudanese government to release political detainees.

He further commended the recent U.S. decision of easing sanctions on Sudan, saying that "the first beneficiary of lifting the sanctions is the Sudanese people."

He urged the Sudanese government to fully respond to the U.S. offers for complete lifting of the sanctions.

The NUP leader on Thursday returned to the Sudanese capital Khartoum from his 30-month self-exile in Egypt.

Al-Mahdi left Sudan to France more than two years ago following a month in detention at Kober federal prison in Khartoum because of criticisms to Sudan's Rapid Support Forces, before he returned to settle in Cairo after signing Paris Declaration with the Sudanese armed groups in August 2014.