In May, the Biden administration said it would support a temporary suspension of patents and other intellectual property linked to the shots to allow developing countries to produce the Covid-19 vaccines created by big drug companies.

The U.S. was under pressure to help get vaccines to poor countries, which have suffered severe shortages of the shots. This year, confirmed deaths from Covid-19 in the developing world have far outstripped those in rich countries.

However, people close to the negotiations at the World Trade Organization, the forum for discussions on the waiver, say the U.S. hasn’t offered proposals to close the broad gap between the positions of the poor countries and those who oppose a broad waiver. Without the U.S. involvement, they say, a waiver is unlikely. The WTO, with 164 member countries, needs a consensus of all members to make a decision.

A group of more than 60 developing countries, led by South Africa and India, have proposed a far-reaching waiver that would remove protections for intellectual property linked to Covid-19 treatments and tests, in addition to vaccines.

The European Union, home to some big pharmaceutical companies, opposes a full waiver, but says it is open to easing some of current rules on so-called Trade-Related Aspects of Intellectual Property Rights, or TRIPS. Earlier this year, the EU presented an alternative proposal that would lift export restrictions on vaccines and their raw materials, expand manufacturing capacity and make it easier for countries to use existing rules to override patents in some cases.

Drug companies have opposed a waiver, saying it wouldn’t ease the vaccine shortages in the short term, partly due to the complexities of making the new shots.

This spring’s announcement by the Biden administration jump-started months of negotiations at the WTO. Poor countries hoped that there could be a deal on a waiver during the biennial meeting of WTO trade ministers, which kicks off on Nov. 30.

But in closed-door talks at the WTO in recent months, U.S. delegates haven’t specified which measures Washington is willing to support, disappointing officials from poor countries who hoped the U.S. could put its weight behind a deal. As a result, the negotiations are stalled, people close to the talks say.

“The U.S. has really been nowhere in the debate,” said an official from a developing country that supports the waiver. “The U.S. has been constantly saying ‘yes, we need an outcome’ but not saying anything on how that can be achieved.”

Informal discussions are continuing, people familiar with the talks say.

U.S. officials have said the administration’s support for an IP waiver accelerated conversations at the WTO and that the U.S. has helped to facilitate discussions among the members. The U.S. is hoping other countries can find a consensus, without the U.S. taking charge of the debate.

“We said that we support the waiver and the waiver components and that we were prepared to…play our role at the WTO to facilitate text-based negotiations because that’s how the WTO works,” U.S. Trade Rep. Katherine Tai told reporters recently. “That is the role that we have been playing, that we will continue to play.”

She added: “You never put a proposal out there expecting that that is the thing that’s going to come out of the process because it’s got to get through 164 members.”

Ms. Tai noted that the discussions on a waiver reflected a powerful message from developing countries that they needed relief from the pandemic through medical treatments and vaccines. She added, however, that some developing nations felt that a waiver wouldn’t necessarily help them access vaccines quickly.

Ms. Tai said the U.S. hasn’t submitted any proposal of its own on the vaccine waiver, but that it will “bring our best game” to the WTO and try to facilitate a meaningful plan that can be accepted by its members.

An EU spokeswoman said the bloc was actively engaging with both proponents of a waiver “to find solutions that are meaningful for increasing the production of Covid-19 vaccines and medicines while maintaining incentives for innovation.”

Since May, the U.S. has embraced other measures to boost the supply of vaccines to the world’s poorest countries. It has pledged to donate at least 1.1 billion shots by next September and has invested in manufacturing facilities in South Africa, Senegal and India. On Wednesday, it said it would spend billions of dollars to help drugmakers boost vaccine production in the U.S.

In recent weeks, more doses have been flowing to developing countries, a sign, pharmaceutical companies and other opponents of the waiver say, that they have been able to boost production with IP protections in place.

But backers of the waiver say increased global production still leaves poor nations vulnerable to shortages if rich countries mandate multiple booster shots or new variants of the coronavirus require updated vaccines. They also say passing a waiver now would set a powerful precedent for how to ensure access to lifesaving medicines in future health crises.

The U.S. reluctance to take a firm position in the waiver talks appears to be driven in part by divisions in Washington on the best way to boost the availability of vaccines in poorer nations, people close to the WTO negotiations say.

Several Republicans in the Senate, where the administration holds a thin majority, have argued against a waiver, saying it could allow China to copy American innovations. There are also divisions within the administration itself on how hard to encourage pharmaceutical companies to share the IP and other technology needed to make the vaccines, with some influential U.S. progressive groups pushing hard for a waiver.