U.S. President welcomed the ruling by the Supreme Court of the United States striking down key provisions of an immigration law in the state of Arizona.

U.S. President Barack Obama on Monday welcomed the ruling by the Supreme Court of the United States striking down key provisions of an immigration law in the state of Arizona.  But Obama says he is concerned about a remaining provision upheld by the high court.

The court struck down three key provisions of the law the Arizona legislature approved in 2010 as part of a series of measures to stem illegal immigration in the state.

The law made it a crime for immigrants without work permits to seek employment, required immigrants to carry registration documents, and authorized police to arrest any immigrant they believe to be deportable - all three provisions struck down by the Supreme Court.

U.S. Attorney General Eric Holder said the federal government will be watching closely to ensure that the law is not being implemented in a manner that has the purpose or effect of discriminating against the Latino or any other community.

Arizona along with Alabama, Georgia, Indiana, South Carolina and Utah have adopted laws to stem the tide of illegal aliens and control crime seen as directly linked to illegal immigration.