"Last Week Tonight" host John Oliver had one message during his Mother's Day segment Sunday: it's about time that businesses offered employees fair maternity leave

The United States ranks nearly dead last when it comes to benefits for new parents. It is just one of four countries in the world (the others include Lesotho, Swaziland and Papua New Guinea) that do not offer paid maternity leave.

"This is not to say that women don't take leave, they just have to get very creative about doing it," Oliver said during his 12-minute monologue on his satirical late night show. 

U.S. federal law requires that employers offer eligible parents up to 12 weeks of unpaid leave. In order to be eligible, however, employees must meet certain requirements such as working at an organization of 50 people or more, having worked there for more than a year and holding a full-time position there.

This means that 40 percent of working mothers aren't covered by the federal law, Oliver pointed out. As a result, many stitch together vacation time and sick days in order to take leave. 

Footage from the debate over the 1993 Family and Medical Leave Act reveals that many lawmakers believe extending parental employment benefits can cost jobs, can be a "suffocating regulatory burden" and are antigrowth. 

Generally, states are left to create their own family leave policies. In 2002, California became the first state to require businesses to offer employees six weeks of partially paid leave. A survey later found that 90 percent of companies reported that the law resulted in positive or neutral effects, Oliver said.

"In California it worked. And yet only two other states [Rhode Island and New Jersey] have followed their lead. And that may be because any legislation that specifically seeks to support women often faces vocal opposition," he said.

To conclude, Oliver rolled a Mother's Day-themed public service announcement video: "Mothers. We owe everything to them. They gave birth to us. They nurtured us. They made us who we are. And this mother's day, we have just one thing to say to all the mothers out there: get the f--k back to work."

He also offered one last, sincere, punchline: "You can't go on and on about how much you love mothers and then fail to support legislation that makes life easier for them," he said.