Some observers are concerned that complicated technical details, the sheer volume of work and possible legislative hurdles could delay ratification of a new START agreement.

VOA: standard.2009.04.02

He says the launch delay at this late stage appears political rather than technical, since it comes just a day after Presidents Obama and Medvedev discussed the issue in Singapore.

VOA: standard.2009.11.16

Pimentel of Brazil said he expects leaders to approve the creation of a development bank, agreement on technical issues might delay any signing at the Durban summit.

NPR: China, Brazil Sign Local Currency Trade Deal

In a statement, Network Rail blamed the delay on "technical issues" that need resolving with Siemens, the company supplying the new signalling system.

BBC: NEWS | UK | England | Hampshire | Rail repairs overrun indefinitely

Randy Baseler, vice-president of marketing for Boeing Commercial Airplane Group, says the delay is due to technical considerations.

ECONOMIST: Boeing v Airbus