Sudan leader Omar al-Bashir had been due to arrive in China early on Monday, with rights groups outraged that Beijing would host a man wanted by the International Criminal Court (ICC) for crimes against humanity during Sudan's civil war.
Chinese foreign ministry staff told AFP that Bashir's plane had been "delayed." Six hours after his scheduled arrival, they said they still had no updated information on when Bashir would land. "This afternoon's activities have been cancelled," a ministry staff member said, referring to a scheduled late afternoon meeting with Hu.
Bashir was due to stay in China -- a key supporter of the regime in Khartoum -- until Thursday. Staff at Sudan's embassy in Beijing said they had no information on the matter.
The ICC has issued arrest warrants for Bashir for genocide, crimes against humanity and war crimes in Sudan's western Darfur region, where about 300,000 people have died since 2003. He is the first sitting head of state to be targeted by an ICC warrant.
ICC statutes dictate that any member country should arrest Bashir if he visits. China is not a party to those statutes.
Bashir had cancelled plans to attend a summit earlier this month in Malaysia, which declared this year that it intends to recognise the ICC's jurisdiction to show its commitment to fight crimes against humanity.
China is a major military supplier to the regime in Khartoum and the biggest buyer of the country's oil, although the majority of Sudan's oil fields are located in the south, which will become independent next month. Beijing last week defended the visit.
"In recent years President Bashir has made many visits to other countries and was warmly welcomed," foreign ministry spokesman Hong Lei told reporters. "It's quite reasonable for China to invite the head of a state that has diplomatic ties with China to come for a visit."
New York-based Human Rights Watch said Bashir's visit to China was "an affront to victims of heinous crimes committed in Darfur" and urged Beijing to withdraw its invitation -- or arrest Bashir when he arrived.
Amnesty International said earlier this month China risked becoming a "safe haven for alleged perpetrators of genocide" if it hosted Bashir. Bashir was also slated to hold talks later in the week with other top officials.
Topics on the agenda were likely to include possible fresh aid to Sudan and problems in Abyei, a disputed border area claimed by Bashir's Khartoum-based northern Sudan regime and a rival government in the south.
Khartoum government troops occupied Abyei on May 21 and tens of thousands of people have since fled to the south. The north and south reached an accord last Monday under which border areas will be demilitarised.