Psalm 2:8 Ask of Me, and I will give You The nations for Your inheritance, And the ends of the earth for Your possession.
Psalm 2 is a Messianic Psalm and refers to the Lord Jesus Christ who will one day be king over all the earth. God will give to Jesus all nations of the earth for the purpose of filling the earth with his Father's glory.
Revelation 11:15Then the seventh angel sounded: And there were loud voices in heaven, saying, "The kingdoms of this world have become the kingdoms of our Lord and of His Christ, and He shall reign forever and ever!"
Here are links to information which will assist in answering your question:
The Kingdom of God on Earth: https://www.thisisyourbible.com/library/show/170
Christ is Coming:https://www.thisisyourbible.com/library/show/184
I hope you have found this helpful.