Sudan's President Omar al-Bashir has ruled out talks with South Sudan on the simmering border conflict that has prompted fears of all-out war.
He was speaking during a visit to the major oil field and border town of Heglig, which was occupied by South Sudanese troops nearly two weeks ago.
South Sudan says it has withdrawn from Heglig, but Sudan says its army forced them out, killing 1,000 soldiers.
Earlier, Sudanese jets bombed a border area in South Sudan, witnesses said.
"We will not negotiate with the South's government, because they don't understand anything but the language of the gun and ammunition," Reuters news agency quoted Mr Bashir as telling troops on his arrival in Heglig.
The past few months have seen sporadic fighting in the oil-rich areas along the two countries' undemarcated border, prompting concern the violence could escalate into a full-blown war.
US President Barack Obama has said both countries "must have the courage" to return to the negotiating table and resolve their differences peacefully.
First came the throbbing noise of a jet engine. Then the dull thump of one, then several, explosions.
People ran into sturdy buildings. Others, cooler, sauntered into the shade, sure this was not their time to die. From all over Bentiu came the irregular chatter of small arms fire, as soldiers and men in uniform tried to take out the warplane.
The men continued to fire for some time after the sky was clear. It was a futile, one-way conversation. But the jets did not achieve their aim either - the bridge that links Bentiu to Rubkona, and then the oil fields and the disputed border from the north, is still intact.
As on several previous failed attempts, civilians suffered from the bridge's good fortune. At least one was killed, his body a grotesque, mangled lump, in Rubkona market. It is far enough from the bridge for everyone here to believe this was a deliberate attempt to target civilians.
Sudan's military commander Kamal Marouf said that 1,000 southern soldiers had been killed during the fighting for Heglig, reports the AFP news agency, whose correspondent saw an "uncountable" number of dead bodies wearing South Sudanese military uniforms.
President Bashir told assembled Sudanese troops the vultures "have been well fed and are relaxing in the shade under the trees" in Heglig, according to Sudanese state TV.
But these casualty figures were rejected by South Sudan's Information Minister, Barnaba Marial Benjamin, who told the BBC's Focus on Africa programme that "not even a single SPLA soldier have they killed".
On Monday, Sudanese warplanes dropped bombs near the South Sudanese border town of Bentiu, killing at least one person, according to witnesses.
Taban Deng, governor of Unity state, said the bombs fell on a key bridge, which leads to the border, and a market between the state capital Bentiu and the nearby town of Rubkona.
The witnesses described seeing a huge plume of smoke rising from a market and the body of a dead boy.
Mr Deng said that three civilians had also been critically wounded in the raid and were not expected to survive.
South Sudan's deputy head of intelligence, Mac Paul, described the bombing as a "declaration of war", according to the Associated Press.
South Sudan's military spokesman Col Philip Aguer said that Sudanese bombers had also targeted oil fields elsewhere in Unity state but that the extent of the damage was unclear.
Bentiu residents ran for their lives during the air raid
The attack was condemned by the UN peacekeeping mission in South Sudan and the United States, which called for an immediate end to violence.
A foreign ministry official in Khartoum denied that Sudan had carried out the raid, according to AFP.
Following months of border skirmishes, South Sudan sent its forces into Heglig earlier in April, saying the area was being used as a base for Sudanese attacks on its territory.
Heglig, which used to provide more than half of Sudan's oil, is internationally accepted to be part of Sudanese territory, but the border area is yet to be demarcated.
South Sudan says the area should belong to it, and that the issue should be resolved by international mediation.
Mr Bashir responded to the seizure of Heglig by saying that his main goal was now to "liberate" the people of South Sudan from its rulers, describing the former rebel Sudan People's Liberation Movement (SPLM) government in Juba as "insects" that needed to be eliminated.