BELGRADE – Rudy Giuliani, the former New York mayor who is said to be one of U.S. President-elect Donald Trump’s leading candidates to become secretary of state, has had past dealings with foreign leaders and groups from Serbia to Russia and Iran that could draw scrutiny if he is nominated, RFE/RL reports.

Giuliani criticized former Secretary of State Hillary Clinton for her ties to foreign governments and corporations when she was running for the White House, but critics say his past associations could expose him to the same charges.

Giuliani traveled to Belgrade in 2012 and met with Aleksandar Vucic, Serbia’s current prime minister who was then leader of the Serbian Progressive Party that had been allied with Slobodan Milosevic.

News of Giuliani’s trip prompted Clinton, while she was secretary of state, to write “this is outrageous” in an e-mail that was later leaked and spurred the U.S. Embassy in Belgrade to issue a statement at the time saying the United States wasn’t taking sides in Serbia’s elections.

Giuliani himself views his extensive foreign travel and contacts as a major reason he’s qualified for the top diplomatic job.

“I’ve been in 80 countries, 150 different foreign trips,” Giuliani said in an interview on Fox News on November 15.

“A lot of it for different reasons. Speeches. Security consulting, where I helped bring down crime.”