President Barack Obama plowed back into the "War on Women" at a speech during the Planned Parenthood annual conference Friday, blasting conservatives who have pushed to restrict abortion access at the state level.

"The fact is, after decades of progress, there’s still those who want to turn back the clock to policies more suited to the 1950s than the 21st century," he said. "And they’ve been involved in an orchestrated and historic effort to roll back basic rights when it comes to women’s health."

Noting that 42 states have introduced measures to restrict or regulate abortions — and that North Dakota has effectively banned abortion altogether — Obama called the laws "absurd" and accused pro-life advocates of trying to strip women of their right to health care.

"It’s wrong. It’s an assault on women’s rights," he said, later joking: "When you read about some of these laws, you want to check the calendar; you want to make sure you’re still living in 2013."

The speech laid bare the escalating battle over abortion rights in the United States. In addition to North Dakota; Arkansas, Virginia, Kansas, and Alabama have passed laws this year that severely restrict access to abortion, and at least 19 other states are considering extensive new regulations for abortion clinics and providers.

Pro-life activists have also seized on the grisly murder trial of Philadelphia abortion doctor Kermit Gosnell, who is charged with killing live infants during late-term abortions. Anti-abortion groups have accused Planned Parenthood of knowing about Gosnell's clinics and failing to intervene, and have also used the case to draw attention to problems at Planned Parenthood clinics across the country.

“President Obama blatantly ignored this inconvenient truth about the abortion industry’s horrific lack of oversight, and disparaged the pro-life advocates who wake up each morning with the goal of saving the lives of unborn children and women from the pain of abortion," Susan B. Anthony List President Marjorie Dannenfelser said in a statement following Obama's speech.

While Obama did not mention the Gosnell case during his speech Friday, he was unambiguous about which side he is on in the abortion wars:

"As long as we've got to fight to make sure women have access to quality, affordable health care, and as long as we've got to fight to protect a woman's right to make her own choices about her own health, I want you to know that you've also got a President who's going to be right there with you fighting every step of the way."