Hillary Clinton's trouble-prone African odyssey threw up more controversy last night when she appeared to equate US democracy with Nigeria's corrupt election system.

Speaking in Nigeria, the latest stop on her multicountry tour, the US secretary of state said that Nigeria had troubles with its elections but so too did the US, citing the example of the 2000 Florida recount.

But she went further by singling out Jeb Bush, the Republican governor of Florida at the time and brother of the party's candidate George Bush. The Republicans eagerly jumped on her remarks last night, saying her trip had been full of gaffes and expressed hope she would go to Africa more often.

Clinton, in the capital Abuja, told an audience of civil activists that Nigeria's election system was flawed and "lack of transparency and accountability has eroded the legitimacy of the government and contributed to the rise of groups that embrace violence and reject the authority of the state".

But she went on to draw a parallel with the US. "Our democracy is still evolving. You know we had some problems in some of our presidential elections. As you may remember, in 2000 our presidential election came down to one state where the brother of one of the men running for president was governor of the state. So we have our problems too."

The Republicans will seek to exploit Clinton's comparison of the US elections with those on an African state and for breaking the convention that leaders do not criticise fellow domestic politicians while abroad.

The Democrats claim that George Bush stole the election from Al Gore in Florida but the Republicans insist that the recounts were fair.

Terry Holt, a Republican strategist, told CNN that Clinton had had quite a string of gaffes on the Africa trip. "I hope she goes to Africa more often," he said.

But James Carville, a former adviser to President Bill Clinton, said: "There is not a single thing that is in dispute. There has to be a time when the secretary of state speaks the truth."

The latest row of her seven-country trip came only two days after an outburst in which she turned on a student in the Democratic Republic of Congo who asked her for Bill Clinton's views on the country's politics. She gave a terse reply, saying she was secretary of state and could give her own opinions. Afterwards, it was reported that the student's question had been mistranslated and that he had meant to ask about Barack Obama's views of the country.

But the state department yesterday said this was untrue and the student had simply been nervous and had meant to ask about Obama's views but raised Bill Clinton instead.

The start of Hillary Clinton's trip was overshadowed by her husband's dramatic rescue mission to North Korea to bring home two US journalists who had been held captive since early this year.

The state department stood by Clinton's comments about elections, saying that she made the comparison to stress that, in spite of the arguments in 2000, there had been a peaceful transfer of power.

"The point she is making is that it's about a disputed result and then the willingness of the candidates to accept a flawed result rather than, say resort to violence," PJ Crowley, a state department spokesman, said.

Clinton praised the 2008 US election as an example of how democracy should work.

"I know a little bit about running elections and I have won some elections, and, I have lost some elections," she said. She pointed to her loss to Obama, and the subsequent joining of his administration, as a way forward for Nigeria's next general election.

"In my country the man that I was running against and spent a lot of time and effort to defeat, asked me to join his government. So there is a way to begin to make this transition that will lead to free and fair elections in [Nigeria in] 2011," Clinton said.

She is due to leave Nigeria today for Liberia and end her trip in Cape Verde.