The United States will provide a new $190mn financial package to Ukraine to help reforms in the war-torn country and specifically to bolster the fight against corruption, US Vice President Joe Biden told journalists in Kyiv on December 7.

"It is absolutely critical for Ukraine to root out the cancer of corruption," Biden said at a joint briefing with President Petro Poroshenko, Reuters reported. "Ukraine is on the cusp - what happens in the next year is likely to determine the fate of the country for generations," Biden added.

The vice president arrived in Ukraine on December 6 for top-level talks and to deliver a speech to the Ukrainian parliament on December 8 at which he is expected to reiterate Washington's support for the pro-Western government. But for many local and Western analysts and representatives of Western governments, Biden's arrival coincides with a low ebb of confidence in the efforts of the national leadership to spur on reform and the fight against graft.

The International Monetary Fund (IMF) also announced that the next $1.7bn tranche of its $17.5bn aid package to Ukraine has been delayed amid a dispute with the government over its tax reform plans and the 2016 state budget.

"The US wants to see more progress from the Poroshenko administration, and particularly in the area of fighting corruption, which has emerged now as the number one issue in Ukraine," Timothy Ash, a Nomura strategist in London, said in a note to clients after Biden's speech in Kyiv.

"Biden spoke of the need for the administration to engage civil society, which has been calling out for more progress in areas such as the rule of law – I guess the message was for Poroshenko to listen, as some suggest the president is not as in touch as he could be with the grass roots feeling that progress on the rule of law issue is falling behind," Ash added.