WASHINGTON (REUTERS) - US senators are very close to reaching a deal on legislation to sanction Russia over its actions on Ukraine, including some measures that may take effect before any invasion, two leading senators said on Sunday (Jan 30).

Senators Bob Menendez and James Risch, the chairman and top Republican on the Senate Foreign Relations Committee, said they hoped to move forward on the bill this week.

"I would describe it as that we are on the one-yard line," Menendez said on CNN's State of the Union, using an American football reference meaning very close to the goal.

There is strong bipartisan resolve to support Ukraine and to punish Russia if it invades Ukraine, Menendez said. Asked if an agreement will be reached this week, he said, "I believe that we will get there."

Russia has been building up its forces on Ukraine's borders for months and has demanded Nato pull troops and weapons from eastern Europe and bar the former Soviet state from ever joining the US-led military alliance.

Ukrainian President Volodymyr Zelenskiy supports immediate action and has criticised the West for waiting to impose more damaging sanctions.

The Senate bill would target the most significant Russian banks and Russian sovereign debt, as well as provide more US military assistance to Ukraine.

Some of the sanctions in the bill could take place before any invasion because of what Russia has already done, Menendez said, including cyber attacks on Ukraine, false flag operations and efforts to undermine the Ukrainian government internally.

More crushing sanctions would come if Russia invades, he said, "but the lethal aid would travel no matter what." There are still areas of disagreement between senators from the two parties, especially over whether to impose sanctions on the Nord Stream 2 natural gas pipeline.

"We're working on that. I think that's going to be the last T-crossed, I-dotted before we put them all across the finish line," Risch said.