The phrase "a main border" is correct and usable in written English.
It can be used when referring to a primary or significant border in a geographical, political, or design context.
Example: "The map clearly shows a main border separating the two countries."
Alternatives: "a primary border" or "a principal border".
He and several others took a bus to a main border crossing.
A main border crossing, where goods were being transported to this impoverished town, has been officially closed.
Afghan and Pakistani border guards confronted each other at a main border crossing linking Chaman, in Pakistan, and Spinboldak, in Afghanistan, causing the crossing to be closed for the day, police officials said.
There were also clashes a few miles from the main border crossing into neighboring Tunisia, residents told Reuters.
On the first day of talks between the two sides on Saturday, at a grubby cafe overlooking the main border crossing between Kosovo and Macedonia, Nato officers were struck by how determined the Serbs were to hammer out the military details.
They then seized a strategic town and the main border crossing into Jordan before resuming their gradual advance toward the capital.
Pakistan's attitude toward the U.S., he said, is "if you are building pressure, I'll do the same to counter you". Still, the issue has already created new tensions along the Afghan-Pakistan border, where fighting has broken out several times since Pakistan tightened security after Mansoor's killing and troops tried to erect a new gate at the busy main border crossing.
Norway's border with Sweden, for example, is one of the most frictionless in the world between two countries that do not have a customs union, but it still takes about 20 minutes on average for a lorry to pass through its main border crossing at Svinesund.
The three main Palestinian militant groups -- Hamas, Islamic Jihad and Al Aksa Martyrs Brigades -- staged an unusual joint attack on an Israeli Army post at Erez, the main border crossing between Israel and Gaza, killing four soldiers and registering their clear and violent opposition to the American-led peace initiative.
A16 Afghans to Get Customs Help The Treasury Department will send customs officials to assess the chaotic system at Afghanistan's main border crossings in an effort to help the country gain control of customs revenues.
Mr. Shirzai's men crossed into Afghanistan from Pakistan, at a village called Shinarai, north of the main border crossing of Spinbaldak.
