US Vice-President Joe Biden is due to hold talks with the Ukrainian leadership on Tuesday.

Biden is to meet the country's Prime Minister Arseniy Yatsenyuk and interim President Oleksandr Turchynov.

He is also expected to announce that the US will provide economic and energy-related assistance to the government.

May 25's presidential elections in Ukraine will also be on the agenda, according to the BBC. Other sources suggest help by the US might also include "non-lethal military assistance".

Unconfirmed earlier reports have hinted that Biden, who is the highest-level official to arrive in Ukraine since the start of the crisis, will also approach subjects as expanding shale gas projects to reduce Ukraine's energy dependence.

The official visit to Kiev is aimed at showing support for the leadership, which is struggling to deal with an economic crisis and unrest in the east and south of the country.

It comes amid increased tensions near Ukraine's border with Russia, where a few incidents over the weekend have violated last Thursday's Geneva accord.

At a meeting in Switzerland, Ukraine, Russia, the EU and the US agreed that illegal groups across the Ukrainian territory be disarmed and that pro-Russian protesters occupying buildings in at least nine towns and cities hand down their weapons and withdraw.

Activists have so far refused to abide by the agreement, saying they will remain at their barricades until the government resigns.