In the ninth year of Zedekiah’s reign, Nebuchadnezzar came to Jerusalem. From the massive attack and the personal presence it becomes evident that Nebuchadnezzar is very much offended by the rebellion of Zedekiah. The start of the siege happened in winter, and the winter was not the preferable season to wage war. This is also an indicator of how much it meant to Nebuchadnezzar to deal with Zedekiah and Jerusalem.
Carefully translated, 2 Kings 25:1 sounds like this: Nebuchadnezzar laid siege to Jerusalem. And they built a siege rampart around the city.
This shows that Nebuchadnezzar instructed his soldiers to build the ramparts; his head office was in Riblah, and perhaps he stayed there during the construction of the ramparts.
1 And in the ninth year of his reign, in the tenth month, on the tenth day of the month, Nebuchadnezzar king of Babylon came with all his army against Jerusalem and laid siege to it. And they built siegeworks all around it.