London, Jun 14 (IANS): Hollywood actress Naomi Watts has claimed motherhood is the "hardest thing" she has ever done.

The 44-year-old actress, who has sons Alexander, two, and Kai, 18 months, with long-term partner Liev Schreiber, didn't plan to have children late in life and thinks their closeness in age makes raising them extra difficult, but doesn't regret her life's decisions, reports imdb.com.

"I didn't ever think I would be having kids this late. Then two under the age of two in diapers - it's the hardest thing I've ever done, but the most rewarding," she said.

Naomi didn't find acting success until she was cast in "Mulholland Drive" aged 31, but she still felt comfortably established enough to take time off to have her children.

"I didn't really worry about having time off. My career started late, so by the time I was ready to have children, I felt like I had enough body of work under my belt. I was ready to say, 'OK, let's slow this down a little bit'," she said.