WASHINGTON -- The US Senate on Wednesday voted 51-50 to effectively block a bipartisan resolution aimed at curbing President Donald Trump's authority to use military force in Venezuela, after two GOP senators flipped under intense pressure from the White House.

After senators Josh Hawley and Todd Young reversed their position and left the chamber deadlocked 50-50, US Vice President JD Vance cast the tie-breaking vote on a procedural motion, derailing the measure that would have required the president to obtain congressional approval before taking further military action in the oil-rich South American nation.

Young, who had been in talks with Secretary of State Marco Rubio, told CNN on Wednesday that he received "fairly extensive personal assurances" from the Trump administration over the US role in Venezuela.

Young said the White House will "come to Congress" and seek congressional approval before "any major military operation in Venezuela," adding that Rubio would testify before the Senate Foreign Relations Committee later this month, according to a CNN report.

Hawley also said Wednesday that Rubio assured him that there would not be ground troops sent to Venezuela and that the administration would seek congressional approval if that changed.

The resolution was introduced in the wake of a US military operation in Venezuela that resulted in the capture of President Nicolas Maduro. The US Senate last week voted 52 to 47 to advance the war powers resolution.

Trump had publicly criticized the five Republicans who joined all Democrats to back the bill, saying they "should never be elected to office again."

The president also called each of the five senators to vent his frustration over their votes, said a report from The Hill.