* EU-hopeful says ready to discuss taking quota of migrants
* Hungarian border measures may create bottleneck in Serbia
* Serbian government says adopting action plan (Recasts with call for cash)
By Fatos Bytyci and Aleksandar Vasovic
OHRID, Macedonia/BELGRADE, Sept 4 (Reuters) - Serbia said on Friday it would ask the European Union for direct budget support to deal with an expected bottleneck of migrants as neighbouring Hungary cracks down on illegal border crossings, and Belgrade also offered to take in a quota of refugees.
Hungary's right-wing government says it will cut the flow of migrants over its southern border from Serbia to zero as of mid-September, with a 3.5 metre high fence nearing completion and a raft of measures being adopted by parliament on Friday.
Hungarian Prime Minister Viktor Orban said on Friday Serbia and Macedonia - cash-strapped transit countries for most of over 140,000 migrants registered as entering Hungary this year through the Balkan peninsula - should prepare for a "different era" as of Sept. 15.
Aleksandar Vulin, Serbia's minister of labour and social affairs, said the Belgrade government had adopted an 'action plan' to address the crisis, though he declined to give details.
He urged the EU, which Serbia wants to join, to stump up the cash. The EU has so far paid out 1.7 million euros to help Serbia and Macedonia deal with the massive surge in migrants crossing their borders.
On Thursday, more than 5,000 entered Macedonia from Greece, the United Nations refugee agency UNHCR said.
"We want direct budget backing," Vulin told Reuters. "We pay people who are distributing the aid, doctors, police officers."
Serbia's interior minister, attending talks on the issue in Macedonia, said his country was "prepared to speak about" taking in a quota of migrants.
"As a country that wants to be a member of the EU, this is a good time to show we are prepared for that task," Nebojsa Stefanoviche told Reuters.
He also expressed concern at the effects of Hungary's border measures, which include creating "transit zones" on the frontier where asylum seekers would be held until their requests are processed, and deported if denied.
"This is not helpful in terms of stopping migration," he said in the Macedonian lakeside town of Ohrid. "The only question is how we deal with this and how we are prepared to accept them."
Migration experts warn that while some migrants may be driven to take alternative routes through Croatia and Romania, neither country is a member of Europe's Schengen zone of passport-free travel, meaning many trying to reach western Europe will opt to bide their time in Serbia before finding a way through the fence.
"The action plan is very precise about for how many days we can handle a given number of people," said Vulin. (Writing by Matt Robinson; Editing by Gareth Jones)