Two top U.S. trade negotiators whose jobs had been in limbo in the Senate for six months were put into office by President Barack Obama on an interim basis.

Michael Punke, the U.S. ambassador to the World Trade Organization, and Isi Siddiqui, chief U.S. agricultural trade negotiator, were among 15 nominees given recess appointments by the president.

The long lag had been decried by farm groups and by diplomats at the WTO, who said it was a sign the administration did not take trade negotiations seriously.

U.S. Trade Representative Ron Kirk had acknowledged earlier this month that the Senate's failure to confirm Punke and Siddiqui had handicapped the United States in world trade talks.

Punke and Siddiqui were nominated to their posts in September but action was blocked by a Republican senator.

Action on Punke and Siddiqui was held up by Senator Jim Bunning, a Republican from the tobacco-growing state of Kentucky, because he wanted the Obama administration to prod Canada to change parts of its anti-smoking legislation.

Punke, an international trade lawyer who was a trade official during the Clinton administration, will move to Geneva "immediately," the USTR said in a statement.

Siddiqui had already been working as a consultant to the USTR after leaving his post as a vice president of CropLife America, a trade group for chemical and seed companies.

The Constitution gives the president the tool of recess appointments to fill vacancies without needing Senate approval when Congress is not in session. Recess appointments last less than two years but successive appointments are possible.

Obama's Democrats lost their 60-seat super majority in the Senate in January, denying them the votes needed to overcome procedural delays by Republicans. (Reuters)