Updated

The world's nations began a final push Tuesday for the first legally binding global treaty that would regulate the international arms trade and try to prevent the transfer of weapons to armed groups and terrorists.

The 193-member U.N. General Assembly is expected to approve the treaty, which has been in the works since 2006, when the U.S. voted against the resolution that launched the process. The Obama administration later reversed the George W. Bush administration's position and supported an assembly resolution to hold this year's four-week Conference on the Arms Trade Treaty.

Secretary-General Ban Ki-Moon opened the conference after a delay amid reports of disagreement over the role of the Palestinian delegation. Ban said that while the world has made progress on regulating weapons of mass destruction, work on conventional arms has lagged.

"Our common goal is clear: a robust and legally binding Arms Trade Treaty that will have a real impact on the lives of those millions of people suffering from the consequences of armed conflict, repression and armed violence," Ban said. "It is ambitious, but it is achievable."

Led by the United Kingdom, nations have worked to create a treaty that would promote transparency and accountability in the arms trade and prevent international transfers of arms that contribute to serious human rights violations, armed conflict, U.N. sanctions violations, organized crime and terrorist acts. It would not ban the sale of any kinds of guns.

As the escalating conflict in Syria loomed over the conference, questions remained on whether a final treaty would contain strong human rights provisions or cover ammunition as well.

The foreign ministers of the U.K., France, Germany and Sweden wrote in a Monday editorial in the Guardian newspaper that the treaty "should cover all types of conventional weapons, notably including small arms and light weapons, all types of munitions, and related technologies. It is also of great importance that the treaty includes strong provisions on human rights, international humanitarian law and sustainable development."

In April, the U.S. assistant secretary of state for international security and nonproliferation, Thomas Countryman, reiterated U.S. support for a treaty, but not one that regulates ammunition.

"We want any treaty to make it more difficult and expensive to conduct illicit, illegal and destabilizing transfers of arms," he said. "But we do not want something that would make legitimate international arms trade more cumbersome than the hurdles United States exporters already face."

Supporters of a treaty say it will close loopholes that allow arms dealers to evade the strict laws that already exist in countries like the U.S. and transfer guns through weaker states. Only 52 nations have laws regulating arms brokers, and less than half of those impose criminal or monetary penalties for illegal gun sales, according to Oxfam America.

Republicans in Congress have expressed their opposition. Last week, in a letter to President Barack Obama, 130 members wrote that a treaty was "likely to pose significant threats to our national security, foreign policy, and economic interests as well as our constitutional rights." They called for the rejection of any treaty that would prevent the U.S. from supplying arms to allies like Israel and Taiwan.