BRUSSELS, Oct 6 (Reuters) - The European Union on Wednesday agreed to back five-year climate targets at the COP26 climate change conference, where countries will attempt to finalise the rules needed to put the Paris Agreement into effect. At the COP26 summit, to be held in Glasgow from Oct. 31 to Nov. 12, countries will attempt to unblock years of negotiations on the technical rules. One issue they will address is whether their climate targets under the Paris 2015 accord should follow a "common timeframe". Environment ministers from EU countries agreed on Wednesday to support the view that countries should set climate targets every five years. Some EU states, including Poland, had wanted an option to set 10 years goals. read more The EU will express its preference for five-year targets "only in the case all parties would be required to do so and in a manner consistent with the European climate law," the ministers said in a statement. The EU decision boosts the negotiating position of the United States, African countries and small island states, who also support five-year climate pledges. They say the shorter five-year cycle would keep up pressure on countries to set ambitious targets, and help track whether they are cutting emissions fast enough to avert catastrophic climate change. They also worry that 10-year pledges could let countries with weaker climate goals fly under the radar for a whole decade. China and India are among the countries opposed to a single timeframe. Setting a Paris Agreement pledge every five years would not necessarily change the EU"s legally binding targets to cut emissions by 2030 and 2050. Brussels will also set a 2040 emissions-cutting target. For example, the EU could submit a 2035 climate pledge to the U.N. that would estimate where its emissions need to be that year, to stay on track for its 2040 goal. Reporting by Kate Abnett; Editing by Hugh Lawson