Jeremiah 33

In prophesying again concerning the last days, Jeremiah writes -

"In those days, and at that time, will I cause the Branch of righteousness to grow up unto David; and he shall execute judgment and righteousness in the land.
16 In those days shall Judah be saved, and Jerusalem shall dwell safely: and this is the name wherewith she shall be called, The LORD our righteousness.
17 ¶ For thus saith the LORD; David shall never want a man to sit upon the throne of the house of Israel;
18 Neither shall the priests the Levites want a man before me to offer burnt offerings, and to kindle meat offerings, and to do sacrifice continually."  (Old Testament | Jeremiah 33:15 - 18)

These last few verses suggest to me that there will always be a prophet on the earth as well as non lacking in  priesthood leaders, and those that hold the priesthood adding -

"As the host of heaven cannot be numbered, neither the sand of the sea measured: so will I multiply the seed of David my servant, and the Levites that minister unto me."  (Old Testament | Jeremiah 33:22)

But even so, of those that have made covenants with the Lord and have not kept them -

"...thus saith the LORD; Ye have not hearkened unto me, in proclaiming liberty, every one to his brother, and every man to his neighbour: behold, I proclaim a liberty for you, saith the LORD, to the sword, to the pestilence, and to the famine; and I will make you to be removed into all the kingdoms of the earth."  (Old Testament | Jeremiah 34:17)

In my mind, the Lord is saying that if by disobedience we free ourselves from our covenants, the Lord is not bound to keep his promises for -

"I, the Lord, am bound when ye do what I say; but when ye do not what I say, ye have no promise."  (Doctrine and Covenants | Section 82:10)

One last thought, as we are aware that the Lord called Lehi to preach repentance unto Judah in the days of Jeremiah, Jeremiah comments of what the Lord tells him to say -

"I have sent also unto you all my servants the prophets, rising up early and sending them..."  (Old Testament | Jeremiah 35:15)

Obviously, Lehi was one the servants.