Large numbers of refugees and migrants from the Middle East have been arriving in Croatia from Serbia by bus after Hungarian authorities closed the border with Serbia and Serbian authorities started redirecting them to Croatia.
Hungarian Prime Minister Viktor Orban said on Wednesday that his government would put a fence along its border with Croatia and Romania as well to prevent illegal entries by migrants headed for rich countries such as Germany and Sweden.
"You can expect changed relations between Croatia and Hungary soon. That will be a much bigger issue than relations between Serbia and Croatia," Vucic said in Washington on Thursday.
"The Hungarians have announced that they will erect a fence along the border with Croatia, but this is not only about the fence. Just wait and see what will happen," said the Serbian PM visiting the United States.
According to media in the northern Serbian province of Vojvodina, refugees who have been blocked at border crossings with Hungary are moving in large numbers towards Croatia. Local officials expect that by Thursday evening the border crossings Horgos 1 and Horgos 2 will be completely empty after 3,500 refugees have been transferred to Croatia by bus.
Vucic said that there were no problems in cooperation with Croatia, where 7,300 refugees arrived from Serbia by Thursday morning.
"Our ministers of the interior have been in touch and the prime ministers will be too, if necessary," said Vucic.
Vucic said that US Secretary of State John Kerry had commended Serbia for how it was coping with refugees on its border and added that he expected the EU to find a comprehensive solution to the problem.
"Then we, too, will be able to comply with that solution, rather than protecting and defending European values while the conduct of some EU member-states is anything but European. That is something we cannot understand and accept," he said, alluding to Hungary.
The Hungarian police on the border crossing Horgos-Roszke on Wednesday used truncheons, water cannons and tear gas on thousands of refugees after several hundred of them, determined to enter Hungary, broke through a blockade on the Hungarian side that had been additionally reinforced with barbed wire and a mobile metal fence.
The police managed to return the migrants to Serbian territory even though they threw stones, laths and plastic bottles at them.
At midnight on September 15 Hungary closed its border after the entry into force of an amended border law that envisages prison sentences for people attempting to enter Hungary illegally.