The Americans will elevate guest stars Annet Mahendru ("Nina") and Alison Wright ("Martha") to series regulars for Season 2, which is expected to begin production in the fall. As previously announced, Susan Misner ("Sandra Beeman") will also be upped to series regular.

Here's what executive producers Joe Weisberg and Joel Fields had to say about the promotions.

"Annet Mahendru has been a revelation as Nina, bringing the character to life with a rich and subtle depth that keeps you guessing as to what's really percolating under the surface. And Alison Wright's portrayal of Martha is heartbreakingly real at every turn. We are thrilled to add them to our outstanding company of actors."

Annet Mahendru will reprise her role as "Nina," the beautiful and mysterious Russian spy who is intimately involved with FBI Agent Stan Beeman (Noah Emmerich), both personally and professionally. Of East Indian and Russian descent, Mahendru speaks six languages. Her other television credits include 2 Broke Girls, Mike & Molly and Big Time Rush. She also appeared in the feature film Escape from Tomorrow.

Alison Wright will return as "Martha," the delightfully oblivious FBI secretary who has unwittingly married Soviet Directorate S Officer Philip Jennings (Matthew Rhys), believing him to be a Counterintelligence agent named "Clark." Wright, who made her television debut with The Americans, began her career at the age of seven, performing in musical theater productions in her native UK. She appeared in the feature film The Nanny Diaries and is a member of New York's Barrow Group Theatre Company.

Set in 1981 just after Ronald Reagan is elected president, The Americans, starring Keri Russell, Matthew Rhys and Noah Emmerich, is a drama series about the complex marriage of two KGB spies posing as Americans in suburban Washington D.C. Created and executive produced by Joe Weisberg (Falling Skies), a former CIA agent who went on to become an accomplished author, The Americans is produced by Fox Television Studios and FX Productions. Joel Fields and Graham Yost are also executive producers, along with Amblin Television heads Justin Falvey and Darryl Frank. The most critically acclaimed new show of the year, The Americans recently concluded its freshman season.