Ukrainian security officials have renewed their request for U.S. weapons while meeting with a visiting congressional delegation headed by House Democratic leader Nancy Pelosi.

The United States has provided training and nonlethal aid to Ukraine, but has stopped short of supplying any offensive weapons to the Ukrainian armed forces for their fight against Russian-backed separatists in the east of the country.

The head of Ukraine's National Security and Defense Council, Oleksandr Turchynov, stressed during Wednesday's meeting that "only a strong Ukrainian army armed with modern weapons can stop the aggressor and be an influential factor for peace and stability in Europe," according to a statement released by the council.

It quoted Pelosi saying in response that the U.S. was ready to support Ukraine. There was no specific mention of weapons.