Sen. Lindsey Graham revealed he does not agree with Donald Trump's abortion stance despite being one of the former president's biggest allies in the U.S. Senate.

After Trump announced on Monday his policy proposal that he would give the power to the states to determine laws surrounding abortion, Graham posted a lengthy statement to X, formerly Twitter, to express his opposition.

'I respectfully disagree with President Trump's statement that abortion is a states' rights issue,' the South Carolina senator wrote.

He added as part of the thread: 'I will continue to advocate that there should be a national minimum standard limiting abortion at fifteen weeks because the child is capable of feeling pain, with exceptions for rape, incest and life of the mother.'

Trump released a four-minute video on his Truth Social account on Monday with a long-anticipated announcement on his proposal for how he would handle abortion if given a second term in 2024.

The former president said it should be up to the states to determine the laws and he would not support a federal-level ban after the Supreme Court overturned Roe v. Wade in June 2022 and opened the door for more strict abortion laws across the country.

This disappointed those most staunchly pro-life who say it does not go far enough.

It also follows reports that Trump was considering supporting a 15-week ban on abortion – meaning women would not be able to terminate their pregnancy legally after the first trimester.

'We have abortion where everybody wanted it from a legal standpoint, the states will determine by vote or legislation or perhaps both, and whatever they decide must be the law of the land,' Trump, 77, said in the video.

Graham announced in his X thread on Monday that he would be introducing legislation that would require abortion providers to administer anesthesia to unborn children if a mother is getting an abortion at 15 weeks.

'It is common medical practice to administer anesthesia to operate on an unborn child at fifteen weeks to save their life,' he noted.

Susan B. Anthony Pro-Life America said in a statement on Monday that the group is 'deeply disappointed' in Trump's position and said giving the issue to the states 'cedes the national debate to the Democrats.

The group said it will still 'work tirelessly to defeat President Biden' in November.

Sen. Graham said: 'Dobbs does not require that conclusion legally and the pro-life movement has always been about the wellbeing of the unborn child – not geography.'

'The states' rights only rationale today runs contrary to an American consensus that would limit late-term abortions and will age about as well as the Dred Scott decision,' the South Carolina Republican added.

'The science is clear – a child at fifteen weeks is well-developed and is capable of feeling pain.'

The Dred Scott Supreme Court decision in 1857 determined that the U.S. Constitution did not apply to black people in America. Graham is suggesting that not extending constitutional rights to fetuses in their second trimester and beyond is just as bad.

Graham also said in his Monday X statement that it is not unusual for countries to have nationwide bans on abortion.,

'Forty-seven of fifty European nations have national limits on abortion between twelve and fifteen weeks,' he wrote. 'This is the civilized world's position.'