US Secretary of State Hillary Clinton on Friday pressed Sudan for a definitive end to bombings against South Sudan, after Khartoum said it would comply with a UN call to end the violence.

"Together we need to keep sending a strong message to the government of Sudan that it must immediately and unconditionally halt all cross-border attacks, particularly its provocative aerial bombardments," Clinton told a meeting with Chinese leaders, according to her prepared remarks.

Clinton was taking part in annual talks with China, which has come under strong US criticism in recent years for its support of Sudan's President Omar al-Bashir, who faces an international arrest warrant on genocide allegations.

But Clinton welcomed recent moves by China, which has reached out to South Sudan with political and economic support. South Sudan controls much of the region's oil potential and China is a major energy importer.

In a joint statement after the talks, the United States and China noted "the importance of encouraging a peaceful relationship and a productive dialogue between the governments of Sudan and South Sudan on all bilateral issues."

China joined the United States in a unanimous UN Security Council resolution that urged Sudan and South Sudan to halt hostilities in the wake of fighting that has raised fears of a return to all-out war.

Sudan's foreign ministry said Thursday that it would cease hostilities in line with the resolution but reserved the right to defend itself against "aggression" from the South.

South Sudan became independent in July last year, raising hopes internationally for a peaceful end to one of Africa's bloodiest conflicts that has claimed more than two million lives.

But tensions have flared amid an insurgency in Sudan's South Kordofan state, with border clashes erupting in late March and South Sudan occupying the strategic Heglig oil field for 10 days.