KIEV, Sept. 29 - Ukraine should ramp up economic and anti-corruption reforms to pave the way for continued support from whoever wins the U.S. presidential election, U.S. Secretary of Commerce Penny Pritzker said on a visit to Kiev on Thursday, Reuters reported.

While acknowledging the progress Kiev's Western-backed leadership has made since taking power after a 2014 uprising, Pritzker said there was more work to be done and that the former Soviet republic had a limited window to implement reforms.

Ukraine's international backers have propped up its economy with a $40 billion bailout package after Russia's annexation of Crimea in 2014 and the outbreak of a pro-Russian separatist insurgency that has killed more than 9,600 people.

The International Monetary Fund in September released a further tranche of aid as part of that package, which was swiftly followed by a $1 billion loan guarantee from Washington.

Ukraine's new government under Prime Minister Volodymyr Hroysman has taken some politically sensitive decisions, including hiking gas prices, but overall progress on reforms and tackling entrenched graft has been patchy.

Companies such as Citigroup want to expand in Ukraine but are waiting for Kiev to tackle issues such as strengthening intellectual property rights and reforming the country's tax and customs services, Pritzker said.

"There's good news, but there's more work to do. And part of our message to the government is: the intensity and urgency needs to continue and be ramped up, because this isn't going to be an opportunity for ever," Pritzker said in an interview.

The prospect of Donald Trump - who has praised Russian President Vladimir Putin as a strong leader -- taking over in the White House has stirred fears in Ukraine that U.S. policy could pivot away from supporting Kiev.

Pritzker, a wealthy businesswoman who was the national finance chair for President Barack Obama in 2008 and his campaign co-chair in 2012, declined to comment on the U.S. presidential race directly, but said:

"The point to make to the Ukrainian government is: show progress because that will be something that a new administration will want to latch on to."

Ukraine has urged European leaders to keep economic sanctions on Moscow, which were imposed two years ago over the Ukraine conflict, while some European Union member states have been pushing for them to be lifted.

"I think there currently is support but I think the onus is on the Ukrainian government to continue to show why that support should be sustained," Pritzker said when asked whether there was still a weight of international support for Ukraine.

"It's never forever, so they need to do the hard work."

Pritzker was also in Kiev to attend the commemoration of the victims of Babyn Yar, one of the biggest single massacres during the Nazi Holocaust. It has personal resonance for Pritzker, whose own family fled anti-Jewish pogroms in Ukraine in the 1880s. (rt/ez)