Jamie Bell says it feels like ''jumping back into the trenches a little bit'' after welcoming his first child with wife Kate Mara.

The 'Rocketman' actor - who also has five-year-old son Jack with ex-wife Evan Rachel Wood - has broken his silence on welcoming a daughter, whose name is not yet known, with the 'House of Cards' actress ''a couple of weeks ago'', and admitted he's having to get to grips with looking after a baby again.

The father-of-two told 'Extra TV': ''It's kind of jumping back into the trenches a little bit, but, we're very happy everyone is doing well. It's great.

''So much stuff I have forgotten already, I'm kind of having to catch up again.''

Kate announced the arrival of their little bundle of joy by posting a photograph of her daughter's sweet toes on Instagram.

She wrote: ''We had a baby a couple weeks ago... Here are her feet [heart emoji].''

The 'My Days of Mercy' star revealed she was pregnant back in February when she and Jamie attended Sir Elton John's annual AIDS Foundation Oscars Party in West Hollywood, California.

The 'Fantastic Four' actress showed off her growing bump in a short long-sleeved white and silver dress as she posed for pictures at the event.

Pregnancy rumours began to swirl in January, when it was reported that she had been sharing her happy news with friends at the Golden Globe awards.

According to a source at the time, the 'Pose' actress was overheard telling Emily Blunt.

The insider added: ''However she was nervous that people would find out before she made the announcement official as she is already showing.''

Meanwhile, Kate recently said she has become very ''protective'' of the ''incredible'' bond she has shared with the 'Man on a Ledge' star since getting married.

She said: ''I love knowing that I have a partner for life. I feel very proud to call Jamie my husband and to have made that commitment to him ... now that Jamie is legally a part of my family, it's such an incredible thing. I'm very protective of our marriage.''

And the 'Morgan' star revealed she and her 33-year-old spouse keep their relationship strong by sticking to a rule which means they'll never go more than two weeks without spending time together.

She added: ''All the travelling we both have to do for work can make it hard, but we have a rule that we will never go longer than two weeks without seeing each other. Even if we have to spend all day travelling to have just 24 hours together, it's worth it in order to have a strong relationship.''