U.S. Vice-President Joe Biden landed in Ukraine Thursday, U.S. diplomats in Kiev said, ahead of talks with the country's president and prime minister over possible increased assistance amid conflict in the east.

Biden will meet President Petro Poroshenko and Prime Minister Arseniy Yatsenyuk on Friday, the one-year anniversary of the Maidan protests.

Yatsenyuk said earlier Thursday that he hoped for an announcement on fresh U.S. assistance to Ukraine during Biden's visit.

In September, the U.S. announced a fresh $53 million (42 million euro) aid package, including non-lethal military equipment, but Kiev wants Washington to go further and provide lethal assistance.

The secretary of Russia's national security council, Nikolai Patrushev, warned ahead of the trip that the conflict in east Ukraine "will grow" if America supplies Ukraine with weapons.

The Maidan protests on Kiev's main square for closer ties with Europe led to the overthrow of then-president Viktor Yanukovych, prompting Russia to seize Ukraine's Crimean peninsula and eventually triggering unrest in the east.

Pro-Moscow separatist rebel and Ukrainian forces are fighting a drawn-out battle for territory in eastern Ukraine despite a tattered ceasefire agreed in September.

Russia denies giving military support to the separatists but relations between the Kremlin and the West have plunged to a post-Cold War low over the conflict.

In an interview with Kiev's The Day newspaper published Thursday, Biden stressed there was "no military solution to this crisis" and accused Russia of "interfering in the affairs of a sovereign state".

He added: "I will be bringing a strong message of support to the Ukrainian people and government, about which I will have more to say when I am in Kiev."