I agree with the below commentary taken from Amazing Discoveries:
9:25-27 These verses outline events to take place during the
seventy weeks; they also have a definite structure of two groups of three.
1. “unto the Messiah the Prince”
2. “shall Messiah be cut off”
3. “shall cause the sacrifice and oblation to cease”
1. “the street shall be built again, and the wall”
2. “shall destroy the city and the sanctuary”
3. “and that determined shall be poured upon the desolate”
The first group concerns the Messiah, and takes place within the seventy week time period. The second trio concerns Jerusalem and an opposing prince, and is not limited to the seventy weeks.
Verse 27 jumps ahead. The 70th week is yet future. A clear gap is present and the last week was not discussed previously in verse 26.
27 Then he shall confirm a covenant with many for one week; But in the middle of the week He shall bring an end to sacrifice and offering. And on the wing of abominations shall be one who makes desolate, Even until the consummation, which is determined, Is poured out on the desolate."
Who is the HE? Who are the MANY? What is the covenant? Some suggest it is Christ and that Christ took away the sacrifice and offerings by His crucifixion. But did Christ make desolate? No. Christ wasn't even there in AD 70. If the crucifixion was the confirming of a new covenant, why did it last just one week or 7 years? Christ's redemption is permanent, it is an everlasting covenant, not a 7 year covenant so that doesn't make sense either. The 62 weeks and 7 weeks tie perfectly to the command to rebuild the temple and to the anointing of Messiah.
So, do we have further details of this HE who make desolate? Of course, it is the King of the North.
Daniel 11:31 (KJV) And arms shall stand on his part, and they shall pollute the sanctuary of strength, and shall take away the daily sacrifice, and they shall place the abomination that maketh desolate.
Read on what else this man does:
Daniel 11:36 (KJV) And the king shall do according to his will; and he shall exalt himself, and magnify himself above every god, and shall speak marvellous things against the God of gods, and shall prosper till the indignation be accomplished: for that that is determined shall be done.
Does Christ speak against the God of gods? Of course not. Therefore Dan 9:27 refers to the AofD of Dan 11 and 12. Since Daniel's AofD was not Titus then Jesus could not have been referring to Titus either and if Jesus wasn't discussing Titus in Mat 24:15 then He had to be discussing the same AofD that Daniel discusses and this AofD is not only future, it is the same entity that Paul discusses in 2 Thes 2.
Again compare:
Daniel 11:
36 "Then the king shall do according to his own will: he shall exalt and magnify himself above every god, shall speak blasphemies against the God of gods, and shall prosper till the wrath has been accomplished; for what has been determined shall be done.
and...
2 Thes 2:
3 Let no one deceive you by any means; for that Day will not come unless the falling away comes first, and the man of sin is revealed, the son of perdition,
4 who opposes and exalts himself above all that is called God or that is worshiped, so that he sits as God in the temple of God, showing himself that he is God.
These descriptions match perfectly. That "Day" is the Day of the Lord - the Day Christ returns and just as that is future, so is the Man of Sin and so is the Abomination of Desolation spoken of by Daniel and Christ.