WASHINGTON — "It took me more than 10 years to become a U.S. citizen," said Mark Rozario. "God is good!"

Rozario, a Catholic, immigrated to the United States from Bangladesh with a work visa, in 2002. During a naturalization ceremony June 18 at the National Archives in Washington, he expressed his sense of relief at finally getting his citizenship.

"The process was hard," he told Catholic News Service. "I had to wait and wait. I got it, at last."

Rozario, who works at an architectural firm, said his main support throughout the naturalization process has been his employer. "They helped and stood by me," he said.

Rozario mentioned that his dream of becoming a U.S. citizen was the engine of his hope during the long wait for naturalization. As he put it, "It has always been a dream for me. I knew, even, before I came that the U.S.A. was a country of opportunities and I wanted to be (one of) its citizens," he said.

First lady Michelle Obama, who delivered the keynote address, expressed her support for the new citizens, and encouraged them to fully embrace their American nationality with pride.

"No matter what your story, from this day forward, for the rest of your lives, you will always be able to say, 'Yes, I am an American citizen,'" she said.

"As the newest Americans-by-choice, you, too, will play an important part in shaping our history," she added.

Naturalization ceremonies are the final step in the journey to U.S. citizenship. Each year, between 600,000 and 700,000 immigrants become citizens, said Joanne Ferreira, spokeswoman for the U.S. Citizenship and Immigration Services.

The naturalized citizens represented more than 40 countries, including Afghanistan, Israel, Pakistan, Cuba, Venezuela, Egypt, Algeria, Bolivia and Zimbabwe.

"As citizens we do not shut the doors of opportunity behind us. We preserve the opportunity of America," said Obama, noting that other than a few ethnicities, most Americans can trace their ancestry to an immigrant.

Later, a woman from Hungary who simply wanted to identify herself as Nicky called the process of getting her citizenship "sweet and short." She told CNS that four months after her application to be a U.S. citizen, the Citizenship and Immigration Services granted it to her. Nicky is married to an American.

"You came here today as citizens of 44 different countries, and you'll leave here as citizens of one great nation -- the United States of America," said Michelle Obama. "And I hope that you never take that for granted," she added.

Secretary of Homeland Security Jeh Johnson administered the oath of allegiance, which completes the process of becoming a U.S. citizen.