Macedonia has closed its border "completely" to refugees and Hungary said it will increase border security with more troops on Wednesday, a day after some Balkan countries announced new border restrictions.
"Macedonia will act according to the decisions taken by other countries on the Balkan route," an Interior Ministry spokesman said.
Macedonia had been allowing small numbers of Syrians and Iraqis through but stopped this after its neighbours tightened their policies.
"We have completely closed the border," a police official told Reuters.
Hungary's Interior Minister Sandor Pinter said "Hungary will strengthen protection of its borders, and we declare a crisis situation due to migration for the entire country."
He said Hungary was also making preparations along its border with Romania to erect a fence there if needed within 10 days. Hungary has already built a fence on its borders with Serbia and Croatia.
Slovenia, Croatia and Serbia also said on Tuesday that they would place new restrictions on the entry of refugees, putting extra obstacles in the way of those trying to reach the European Union via the Balkans.
"From midnight, there will be no more migration on the Western Balkan route as it took place so far," the Interior Ministry of EU member Slovenia said in a statement.
Non-EU member Serbia said Slovenia's decision meant "a closure of the Balkan route" for refugees and said it would follow suit. "Serbia cannot allow itself to become a collective centre for refugees, so it will harmonise all its measures with those of the EU member states," the Interior Ministry said in a statement.
On Monday, EU leaders agreed in Brussels that member states restoring order to the Schengen Area would mean that Slovenia would bar passage to refugees except those who planned to request asylum in the country or who sought entry for humanitarian reasons, which would be individually assessed.
Only about 460 have requested asylum in Slovenia, which with 2 million people is the smallest country on the Balkan refugees route. About 10 of those refugees have so far been granted asylum in the country.
Croatia's Interior Minister, Vlaho Orepic, confirmed late on Tuesday that the former Yugoslav republic, which is an EU member but not part of the Schengen area, will also apply new rules meaning that only those travelling with valid documents and visas will be able to enter.
Around 475,000 refugees have arrived in Slovenia, a small Alpine country, since October, when Hungary closed its border with Croatia and pushed the refugee route west. Most refugees continued on to Austria and other northern European states.
Nevertheless, the United Nations refugee agency says there are around 1,500 refugees in Macedonia and about 1,000 in Serbia. These refugees could be left stranded by the new border restrictions.