British Prime Minister Gordon Brown visited US President George W. Bush on Thursday and the main issue discussed by the heads of state concerned Iran. Bush and Brown seized the opportunity and warned Iran of further sanctions that would block the foreign investment in the Middle Eastern country.

Both leaders urged Tehran government to halt its nuclear program which, according to the chief of the U.N.'s nuclear watchdog agency, is slowly bringing Iran to the day when it will be able to assemble nuclear weapons.

"They have proven themselves to be untrustworthy," Bush said and the Briton added:

"Iran has not told the truth to the international community about what its plans are."

Before arriving in Washington to mark what he labeled as the “special relationship” between the UK and the US, Brown also met with the candidates who are now battling to succeed Bush.

The British Prime Minister received Senators Hillary Rodham Clinton and Barack Obama, the Democratic contenders, and Senator John McCain, the presumptive Republican nominee, at the British ambassador’s residence.

When asked about the future of the relations between the two countries and which of the candidates he would prefer to follow Mr. Bush at the White House, Brown said:

“It is for Americans to decide who their president is going to be,” he said.

“What I was convinced of, after talking to each of them and talking about the issues that concern them and concern the world, is that the relationship between America and Britain will remain strong, remain steadfast.”

However, both Bush and Brown used the expression "special relationship" several times when referring to the ties between their countries, ties that have been strong since the days of Winston Churchill and Franklin D. Roosevelt.