U.S. Senate Democrats on Wednesday will unveil a bill that would impose sweeping sanctions on top Russian government and military officials, including President Vladimir Putin, and key banking institutions if Moscow engages in hostilities against Ukraine, Senator Robert Menendez said.

The proposed legislation includes provisions to help bolster Ukraine’s security and encourages the United States to "consider all available and appropriate measures" to ensure the Russia-to-Germany Nord Stream 2 pipeline - a "tool of malign influence of the Russian Federation" - does not become operational.

"This legislation makes it absolutely clear that the U.S. Senate will not stand idly by as the Kremlin threatens a re-invasion of Ukraine," Menendez, the Democratic chairman of the Senate Foreign Relations Committee, said in a statement. Menendez will introduce the bill on Wednesday.

Russia has amassed about 100,000 troops on Ukraine's border and Washington is trying to dissuade Moscow from re-invading the country.

The bill, first reported by the Washington Post, would also target companies in Russia that offer secure messaging systems, such as SWIFT, which banks use to exchange key information with other financial institutions.

Nearly two dozen Senate Democrats, including Majority Leader Chuck Schumer, have endorsed the bill, a spokesperson for Menendez said.

A spokesperson for the National Security Council told the Washington Post that the White House supports Menendez's bill, which would "trigger severe costs to Russia's economy" if Russia goes ahead with an invasion.

Another bill sponsored by Republican Senator Ted Cruz, will "not counter further Russian aggression or protect Ukraine," the spokesperson said.

Cruz struck a deal with Schumer last month, in which the Texas senator released his hold on dozens of President Joe Biden's ambassadorial nominees. Cruz's bill will be put to a vote this week, but it requires 60 votes to pass, a high hurdle in the evenly divided Senate.

The Menendez bill provides an alternative for Democrats who support sanctions on the $11 billion Nord Stream 2 pipeline, which is completed but waiting approvals from Germany, and makes it harder for the Cruz bill to pass.

Many Democrats have supported sanctions on the pipeline as it would bypass Ukraine, depriving the country of transit fees.

Cruz's bill would slap sanctions on the pipeline within 15 days of passage, regardless of whether Russia reinvades Ukraine, and would allow Congress to vote to reinstate sanctions should the president waive them.

The pipeline, backed by Russia's state gas company Gazprom , would provide fuel to Germany, Europe's largest economy, which is shutting coal and nuclear plants, as well as to other large countries.

Several Democratic senators said late on Monday, after meeting with Biden administration officials, that they believe the Cruz sanctions on Nord Stream 2 could harm relations with Germany. 

(Reporting by Shivam Patel in Bengaluru and Timothy Gardner in Washington; Editing by Chizu Nomiyama and Paul Simao) ((Shivam.Patel@thomsonreuters.com;))