The FTSE 100 opened firmly in positive territory on Friday morning ahead of critical talks between US leaders this weekend.Stocks tracked Asian markets higher overnight with Japan's Nikkei finishing its final session of 2012 up around 0.7% (Japanese markets are closed on Monday). This means that the index has risen nearly 23% this year, its best annual performance since 2005."With low volumes due to the seasonal break, activity is likely to be subdued for the course of the session and traders are again unwinding positions before fingers are burnt," said market strategist Ishaq Siddqi from ETX Capital.Markets finished flat yesterday after Senate Majority Leader Harry Reid said that "nothing's happening" in regards to talks to avert automatic spending cuts and tax increases. However, President Barack Obama is to meet congressional leaders today while Republicans will reconvene on Sunday evening, the first House of Representatives (HoR) Sunday session in more than two years, providing hope that the government can come to some sort of eleventh-hour agreement."This provides a very small timescale for the resolution of the fiscal cliff and thus there is very little room for manoeuvre after months of negotiations and political posturing. The final game of brinkmanship is now reliant upon the Democrats producing a piece of legislation which is likely to be approved by the HoR," said analysts at Alpari this morning. "However, given the unwillingness of the republicans to play ball on previous occasions, as indicated by the rejection of the bill to increase tax rates for those earning above $1m annually, it is not known how far the democrats need to go to put a bill together that will obtain approval."CompaniesAs has been the case for most of this week, corporate news was thin on the ground this morning, with just one FTSE 350 company revealing any significant news. Platinum miner Lonmin fell early on after announcing that its CEO Ian Farmer has stepped down from the company due to a serious illness. "We wish him well with his ongoing treatment and will stay in close touch with him as a valued colleague and friend," said Chairman Roger Phillimore.On the FTSE 100, mining stocks were registering small gains in the opening hour of trade. Kazakhmys, Antofagasta, Fresnillo, Vedanta and Rio Tinto were among the best performers.On AIM, oil explorer San Leon Energy gained after reporting that its Nowa Sol exploration programme in Poland has showed high potential for oil production.US-focused hydrocarbon explorer Caza Oil & Gas jumped after saying that initial production has started at its Forehand Ranch Prospect in Eddy County, New Mexico. Meanwhile, Randall and Quilter has completed the acquisition of Alma Insurance Company after receiving regulatory approval from the Finnish Financial Services Authority. Shares were flat early on.FTSE 100 - RisersKazakhmys (KAZ) 787.00p +1.22%Antofagasta (ANTO) 1,365.00p +1.04%Fresnillo (FRES) 1,902.00p +0.96%Vedanta Resources (VED) 1,181.00p +0.94%Rio Tinto (RIO) 3,573.50p +0.90%SABMiller (SAB) 2,863.00p +0.81%GKN (GKN) 233.90p +0.78%Associated British Foods (ABF) 1,584.00p +0.76%BHP Billiton (BLT) 2,171.50p +0.70%Croda International (CRDA) 2,381.00p +0.68%FTSE 100 - FallersAdmiral Group (ADM) 1,175.00p -1.92%Evraz (EVR) 257.60p -0.69%International Consolidated Airlines Group SA (CDI) (IAG) 187.00p -0.53%Resolution Ltd. (RSL) 250.60p -0.48%Hammerson (HMSO) 494.60p -0.48%British Land Co (BLND) 569.00p -0.44%National Grid (NG.) 702.00p -0.43%BAE Systems (BA.) 341.90p -0.41%Aggreko (AGK) 1,744.00p -0.40%Capital Shopping Centres Group (CSCG) 361.50p -0.39%FTSE 250 - RisersDirect Line Insurance Group (DLG) 218.10p +2.64%New World Resources A Shares (NWR) 308.30p +1.75%Carpetright (CPR) 682.00p +1.64%Bumi (BUMI) 272.70p +1.41%British Assets Trust (BSET) 123.40p +1.31%Raven Russia Ltd (RUS) 63.55p +1.27%Petra Diamonds Ltd.(DI) (PDL) 115.10p +1.14%Salamander Energy (SMDR) 182.90p +1.11%COLT Group SA (COLT) 102.00p +1.09%Dignity (DTY) 1,068.00p +1.04%FTSE 250 - FallersJD Sports Fashion (JD.) 675.00p -4.86%Enterprise Inns (ETI) 100.70p -1.76%Centamin (DI) (CEY) 38.00p -1.63%Phoenix Group Holdings (DI) (PHNX) 542.50p -1.36%Millennium & Copthorne Hotels (MLC) 507.50p -0.98%St. Modwen Properties (SMP) 227.70p -0.96%QinetiQ Group (QQ.) 184.60p -0.91%Galliford Try (GFRD) 738.50p -0.87%Mitie Group (MTO) 265.00p -0.86%Wetherspoon (J.D.) (JDW) 532.50p -0.84%BC