Al Jazeera's Hashem Ahelbarra, reporting from the rally in Khartoum, said al-Bashir was telling his people to get ready to "die for the sake of Sudan".
"I think he knows the option of a diplomatic way out of the crisis is getting slim as time goes on and he's preparing himself and his own people for the worst eventuality, aggression against Sudan.
"Al-Bashir wants to tell the international community that if he's to be charged for war crimes in Darfur, well look what's happening here, people are coming in thousands to cheer their leader, hailed as a hero.
"There's a common belief in Sudan that this [the ICC arrest warrant] is politically motivated and there is a lot of conspiracy theories that this is done by the Americans, the British, the Israelis, and the French," Ahelbarra said.
Al-Bashir's visit to Darfur came a day after Hillary Clinton, the US secretary of state, said he would be held responsible for "every single death" caused by the expulsion of 13 foreign aid groups who he accused of siding with the ICC.
"This is a horrendous situation that is going to cause untold misery and suffering for the people of Darfur, particularly those in the refugee camps," Clinton said of Sudan's decision to expel the aid groups.
"The real question is what kind of pressure can be brought to bear on President Bashir and the government in Khartoum to understand that they will be held responsible for every single death that occurs in those camps."
"Our response [to the ICC] is to bring electricity more buildings, schools, water, more hospitals. We want a reunification of the people"
President of Sudan
International experts say at least 200,000 people have died in Sudan's western Darfur region, while al-Bashir's government says 10,000 have died.
Most of the deaths have been caused by fighting, but hunger and disease have taken their toll, prompting aid agencies to step in and provide humanitarian aid.
Al-Bashir told the people of Darfur that "our response [to the ICC] is to bring electricity more buildings, schools, water, more hospitals. We want a reunification of the people".
The Darfur visit coincided with the appointment by Barack Obama, the US president, of Scott Gration, a retired air force general, as his special envoy to Sudan.
"He's someone with deep experience in the region, who has personal and professional relationships with key leaders and most importantly has a close personal friendship with the president and has his ear," an Obama administration official said.
Gration was often seen with Obama on the presidential campaign trail last year. They got to know each other when Obama visited Africa in 2006 while still a senator.
The US is trying to convince the Arab League, the African Union and countries with influence over Sudan, such as China, to press al-Bashir to let all aid agencies back in, Robert Wood, a state department spokesman, said.
In a meeting last week with Yang Jiechi, the Chinese foreign minister, Obama expressed his "deep concern" about the unfolding humanitarian crisis in Darfur and asked Beijing to put pressure on Sudan's government.
Many African and Arab governments say the ICC's move was counter-productive and hypocritical as it failed to tackle alleged war crimes by Israel against Arabs, or by the United States in Iraq and Afghanistan.
The US, while not a member of the court, supported the decision to indict al-Bashir, who is accused of seven counts of war crimes and crimes against humanity.