A trickle of refugees have been allowed to cross the border from Greece into Macedonia - the first for two days following clashes earlier this week.
Macedonia briefly opened the border crossing overnight, letting around 170 people cross, Greek Police said.
However some 10,000 people remain camped at the crossing, awaiting their turn.
It comes after clashes broke out on Monday as hundreds attempted to storm the border crossing.
Austria's tightening of its border controls has promoted knock-on restrictions further down the migration trail, causing a huge backlog in refugees attempting to reach Northern Europe.
The country has reintroduced border controls and imposed a migrant cap which means just 80 refugees a day are able to claim asylum.
Defending his decision, Austrian chancellor Werner Faymann has said the country "is not a waiting room for Germany."
Slovenia, Croatia, Hungary and Macedonia have put up barbed wire fences and are also limiting the number of refugees they let through, leaving Greece to host thousands of refugees.
So far more than 120,000 have arrived in Greece since the start of the year, with more expected as winter comes to an end.
The Democratic presidential candidate may also have shown his cards on his choice of running mate.
The US president also shared a post on Twitter accusing Dr Anthony Fauci of misleading the public over hydroxychloroquine.
Fears over an impending second wave of coronavirus dominates Wednesday’s front pages.