NEW YORK (AFP) — Republican presidential candidate John McCain on Friday denied his barrage of hardball negative advertisements against Democratic rival Barack Obama amounted to "lies."

The Arizona Senator defended his campaign's tactics against Obama, which claimed his opponent called Republican vice presidential pick Sarah Palin a "pig" and advocated teaching sex education to kindergarten children.

"Actually, they are not lies," McCain said on the ABC television chat show "The View."

The Obama campaign had argued that McCain's camp deliberately misinterpreted Obama's recent comment that Republican claims to represent change were like putting "lipstick on a pig" as a sexist remark aimed at Palin.

"He shouldn't have said it. He chooses his words very carefully, this is a tough campaign," McCain said.

Earlier this week, the McCain campaign debuted an attack ad claiming that as a state lawmaker in Illinois, Obama backed a bill to teach "comprehensive sex education" to kindergartners."

"Learning about sex before learning to read? Barack Obama. Wrong on education. Wrong for your family," the narrator of the advertisement said.

In reality, the legislation allowed local schools to teach "age-appropriate" sex education, meaning that kindergarten kids could be warned about sexual predators and inappropriate touching but not taught about sex.

The Obama camp hit back angrily at McCain over the advertisement.

"It is shameful and downright perverse for the McCain campaign to use a bill that was written to protect young children from sexual predators as a recycled and discredited political attack against a father of two young girls," said Obama campaign spokesman Bill Burton.

"Last week, John McCain told Time magazine he couldn't define what honor was. Now we know why."