Interpol is to vote for its new president on Wednesday, with the US backing a South Korean candidate who Moscow says is part of a last-minute effort to scuttle a Russian frontrunner's chances.
Delegates from Interpol member nations are meeting in Dubai to replace Meng Hongwei, who went missing in his native China in September. Beijing later said Meng resigned after being charged with accepting bribes.
The vote takes place Wednesday morning with the winner expected to be announced shortly after.
The two leading candidates pit a US-backed South Korean against a Russian official who remains the favourite but has unnerved Western nations and some of Moscow's neighbours.
On Tuesday, US Secretary of State Mike Pompeo threw his weight behind Kim Jong-yang, currently the acting president of the global police body.
"We encourage all nations and organisations that are part of Interpol and that respect the rule of law to choose a leader with integrity. We believe Mr Kim will be just that," Pompeo told reporters.
The endorsement came as calls grew within Western nations for Interpol to reject Russian candidate Alexander Prokopchuk -- a Russian interior ministry official and current Interpol vice president -- over fears Moscow could abuse the role to target political opponents.
Critics have raised concerns over Russia's previous applications for Interpol "Red Notices", or international arrest warrants, to target those who have fallen foul of the Kremlin.
Whoever becomes president needs the backing of two-thirds of the votes and will serve out Meng's term until 2020.
Interpol's president chairs its General Assembly while day-to-day operations are handled by the organisation's Secretary general Juergen Stock.
In an open letter this week, a bipartisan group of US senators said choosing Prokopchuk would be like "putting a fox in charge of a henhouse".
"Russia routinely abuses Interpol for the purpose of settling scores and harassing political opponents, dissidents and journalists," they wrote.
Harriett Baldwin, a minister of state at the British foreign office, told parliament on Tuesday that London would support Kim's bid.
Anti-Kremlin figures have also raised concerns, including Alexei Navalny, the Russian opposition leader who has been repeatedly jailed by authorities.
"Our team has suffered from abuse of Interpol for political persecution by Russia," Navalny wrote on Twitter.
"I don't think that a president from Russia will help to reduce such violations."
US National Security Council spokesman Garrett Marquis echoed the endorsement for Kim.
"As recent events show, the Russian government abuses INTERPOL's processes to harass its political opponents," he said on Twitter.
The controversy also comes amid security concerns over accusations of Russian agents attempting to poison an ex-spy in Britain and trying to hack the network of the global chemical weapons watchdog.
Ukraine, deeply at odds with Moscow over its annexation of Crimea and support for separatists, threatened to pull out of Interpol if Prokopchuk prevailed.
Lithuania also said it would consider withdrawing from the network.
Russian presidential spokesman Dmitry Peskov dismissed the US senators' letter as a "vivid example" of an attempt to interfere in the vote.
Moscow's interior ministry denounced a "foreign media campaign aimed at discrediting Russia's candidate".
But two foes of Russian President Vladimir Putin, who have been targeted by international arrest warrants sought by Moscow, also said Tuesday they were launching a bid to get Russia suspended from Interpol for abusing the agency.
The legal challenge was announced by financier Bill Browder, named in multiple Interpol warrants, and Mikhail Khodorkovsky -- a former oil baron who spent 10 years in a Russian jail and now lives in exile in London.
"The Interpol constitution has very specific rules which forbid countries who are serial abusers from using the system," Browder told reporters.
Briefly arrested in Spain this year under a Moscow-issued Red Notice, Browder said the Russian candidacy was an attempt by Putin to "expand his criminal tentacles to every corner of the globe".
He fought for -- and in 2012 secured -- US sanctions against Russian officials believed to be involved in the death of his tax consultant, Sergei Magnitsky.
Magnitsky died in jail in 2009 after accusing Russian officials of a USD 230-million tax fraud.
Russia has rejected the claims and this week announced it was opening a new probe into Browder on suspicion of running a "transnational criminal gang", even suggesting he was behind Magnitsky's death.
Russian prosecutors said he would be put on an international wanted list "in the near future".
Multilingual Prokopchuk worked in tax enforcement before starting as a Russian representative at Interpol in 2006, according to the interior ministry.