Capitol Hill leaders are nearing agreement in negotiations on an annual defense policy bill that would extend 12 weeks of paid parental leave to federal workers, both military and civilian, in exchange for establishing President Trump's space force initiative.

The agreement would trade a major expansion of benefits to federal workers for a legacy initiative of Mr. Trump's. Federal workers currently can take unpaid leave.

Democratic and GOP aides confirmed the developments. The agreement is not finalized and comes after extensive behind-the-scenes battling on the annual defense measure, which has passed Congress every year since the Kennedy administration. Further details were not available.

Get Breaking News Delivered to Your Inbox

The parental leave provision is a victory for federal workers, who would face benefit cuts under Mr. Trump's budget submissions. Those cuts have always been ignored by Congress, though pension changes were approved under GOP control of the House. The parental leave issue was a priority for Democrats such as House Speaker Nancy Pelosi, who weighed in forcefully this week.

Ivanka Trump, the president's daughter and adviser, said Friday that such a provision would "mark a HUGE step forward towards making paid leave a reality for all Americans."

Numerous details regarding the space force program remain to be worked out and funding for the program would be delivered through separate spending legislation that's also taking shape behind the scenes.

The aides requested anonymity because the agreement is not finalized.