nder pressure from the United States, Nigeria has rejected a North Korean offer to buy missiles after Washington raised concerns over the possible purchase from a nation it has labeled part of an "axis of evil," U.S. officials said on Tuesday.

"They were pretty explicit in saying they would not go ahead with this, so I think we are satisfied," a senior State Department official said, describing U.S.-Nigerian contacts about the deal over the last few days.

Nigeria, a U.S. ally and a major oil supplier, did not immediately reassure the United States it would turn down the offer when North Korea first made it last week.

U.S. diplomats then met with the Nigerian government and hinted at possible sanctions if it were to buy the ballistic missiles from the country Washington considers the world's No. 1 exporter of such weapons, U.S. officials said.

Since the Sept. 11, 2001, attacks showed how vulnerable the country was, the United States has sought to clamp down on the trade of missiles and weapons of mass destruction to prevent militant groups from acquiring them.

Africa's most populous nation, Nigeria sees itself as a regional superpower and has been reaching out to Asia in an effort to attract investment and alliances. It says its weapons are needed for security and peacekeeping.

Missile sales are a major source of revenue for cash-strapped North Korea, which will later this month resume talks soon with Washington and other nations on dismantling its suspected nuclear programs.