The British former Olympic 1,500 metres champion was elected head of the IAAF last year as the scandal hit the sport following reports by German broadcaster ARD and the Sunday Times newspaper.
"He is the duly elected. I see no alternative to him," Hansen told Reuters on Tuesday.
"Seb is honest and a man of integrity. He has the full support, as far as I know, from all 51 (European) federations."
European federations were by no means overwhelmingly in support of Coe in the presidential vote with many backing his opponent Sergey Bubka, who secured 92 votes to Coe's 115.
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An independent commission for the World Anti-Doping Agency (WADA) revealed widespread, state-sponsored doping in Russia in the first part of a report late last year.
Earlier this month, the commission released the second part which accused the IAAF of having "embedded corruption" at the very top of the organisation under former president Lamine Diack.
Coe has also had to face questions about resignation after having spent seven years as IAAF Vice President under Diack but he has denied any knowledge of his president's alleged activities.
Open support from the powerful European athletics federations will be welcomed by Coe, who also had to drop a long-standing contract with U.S. firm Nike after taking over the IAAF due to calls of conflict of interest.
Diack and his son, Papa Massata, are both under formal investigation in France on suspicion of corruption and money-laundering linked to the concealment of positive drug tests in concert with Russian officials.
Both men have denied wrongdoing and the Russian athletics federation has been banned with the Rio de Janeiro Olympics only months away.
"This was a further wake-up for all of us," Hansen said of the second part of the WADA report.
"We have zero tolerance and we want to increase anti-doping activities. We cannot tolerate that. We will make sure we follow and make sure IAAF follows as well," he added.
(Reporting by Karolos Grohmann, editing by Ed Osmond)
