What does Jeremiah 52:4 mean?

In the ninth year of Zedekiah’s reign, on the tenth day of the tenth month, King Nebuchadnezzar of Babylon marched against Jerusalem with his whole army. They set up camp outside the city and built siege ramps all around it. Jeremiah 52:4 - Modern Text Bible

(Babylon’s army surrounds Jerusalem, beginning a long and desperate siege.)