|Senator John Kerry cautioned that the pact's approval was not yet secured [AFP]
The proposed US deal with Russia on capping nuclear arms has secured enough votes to be put up for approval in the Senate this week.
A procedural vote to stop the debate on the New START treaty was passed on Tuesday with the exact number - 67 - needed to pass.
The treaty, which has been one of the priorities of Barack Obama, the president, will now be voted on on Wednesday.
"This treaty will make America safer and restore our leadership in global efforts to stop nuclear proliferation," Harry Reid, the Senate Democratic leader, said.
However, John Kerry, a Democratic senator who led the floor debate as chairman of the Foreign Relations Committee, cautioned: "This is not over. We have to count every vote."
Democrats needed Republican support to win the vote, and need at least two-thirds of the Senate for the treaty to pass. At least 12 Republicans have said that they will approve the deal.
The treaty is set to reign in Russian and US nuclear arsenals, but needs parliamentary approval in both nations.
Legislators must agree that it will correspond with their national interests, and on Monday Obama made efforts to convince reluctant Republican senators to support it.
Obama lobbied senators by phone to ratify the treaty before January, when five additional Republicans take their elected seats in the Senate, which would further endanger the support of the pact.
Its ratification would be a boost for Obama, particularly as he has faced significant criticism at home on the economy and on health care reform that many see as watered down.
The New START deal would cap nuclear weapons and restart weapons inspections.
Republicans opposing the treaty say the pact would limit US efforts to develop systems like those it plans to deploy in Europe to defend against any limited missile attacks from Iran or North Korea.