Sixty-eight Senators have drafted a letter to U.S. President Barack Obama urging support for an international treaty banning landmines, according to a copy of the letter made public Saturday. The number is one more than the 67 votes that would be needed to adopt such a treaty in the 100-member body, indicating a bipartisan effort rare in a Washington polarized by health care reform and financial stimulus. A similar letter was being circulated in the lower House of Representatives to put added pressure on Mr. Obama for approval. In the letters, legislators note the effectiveness of the 1997 Mine Ban Treaty. In the 10 years since the Convention came into force, 158 nations have signed including the United Kingdom and other ISAF partners, as well as Iraq and Afghanistan which, like Colombia, are parties to the Convention and have suffered thousands of mine casualties, the Senators wrote. The Convention has led to a dramatic decline in the use, production, and export of antipersonnel mines. The letter, circulated by Senators Patrick Leahy and George Voinovich, a Democrat and a Republican, was made public by the U.S. Campaign to Ban Landmines. In November, the White House said its policy was under review and for the time being, there were no plans to join the pact. The United States, China and Russia are among a handful of countries that have refused to join the accord. The Bush administration maintained the mines were essential for national security. The United States has not used or produced landmines in the 12 years since the treaty has existed but continues to keep stockpiles, which would be prohibited under the treaty. It is the only NATO member nation that has not joined the pact. Landmines left over from wars are blamed for thousands of deaths and injuries in the last decade. The United States is the worlds largest contributor to humanitarian landmine cleanup programmes. Since 1993, the United States has given 1.3 billion dollars to landmine removal programmes.