Ukrainian authorities would allow the martial law to expire on December 26 barring a Russian invasion, President Petro Poroshenko told reporters on Sunday.

Last month, Kyiv declared a 30-day martial law order in ten Ukrainian regions after the Russian navy seized three Ukrainian vessels in the Kerch Strait.

"Unless there is a large-scale aggression, an intrusion of Russian military forces into Ukrainian territory beyond the line of conflict (with pro-Russian rebels) and the Crimea administrative border, martial law will not be prolonged," Poroshenko said.

Russia has accused Poroshenko trying to boost his ratings by directing the Navy vessels into disputed waters and prompting an incident with Russia. Poroshenko is expected to run for re-election in March 2019 but is facing an uphill battle. Some observers speculated that the martial law could serve to postpone the vote.

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On Sunday, Poroshenko said that "the military situation would not affect the election" and confirmed the country would start preparing for the vote when the martial law order expires.

At the same time, the Ukrainian president refused to confirm his 2019 presidential run.

"If I decide to run and then it so happens that someone more worthy appears, I would help him," he told reporters.

State employees on the spot over Russian relatives

Also on Sunday, the Ukrainian leader said the Ukrainian counterintelligence agency would check all Ukrainian state employees for relatives with Russian citizenship.

"We have many state employees, including security forces, who have family in Crimea," Poroshenko said. "I have spoken to the State Security chief Vasyl Hrytsak to have the Ukrainian counterintelligence check all state employees, with priority on security forces and investigators."

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The move comes after a corruption scandal involving senior Ukrainian intelligence official Serhiy Semochko, whose family reportedly owns luxury real estate near Kyiv and uses a private helicopter. Semochko's common-law wife and several of his relatives have a dual Ukrainian-Russian citizenship, giving rise to rumors that the operative is paid by Russia.

dj/rc (Interfax, Reuters, Ukrainski Novini)