Was the Prophet's—may Allah's prayers and peace be upon him—concern limited to the people of Mecca and Medina? And why?

The interest of Prophet Muhammad (peace be upon him) was not limited to Mecca and Medina; rather, he cared for all people, as his message was universal for all worlds. He corresponded with kingdoms, inviting them to Islam. He frequently supplicated for his community, and it is narrated in a hadith that he wept and said, "O Allah, my community, my community." Then the revelation came to him: "Indeed, We will please you concerning your community and will not displease you." He also used to pray for his community in every prayer, and he informed that he reserved his supplication as an intercession for his community on the Day of Resurrection, and monotheists among them will attain it.