the company will continue to rely upon debt and capital markets for the majority of any necessary long-term funding not provided by operating cash flows . funding decisions will be guided by our capital structure planning objectives . the primary goals of the company 2019s capital structure planning are to maximize financial flexibility and preserve liquidity while reducing interest expense . the majority of international paper 2019s debt is accessed through global public capital markets where we have a wide base of investors . maintaining an investment grade credit rating is an important element of international paper 2019s financing strategy . at december 31 , 2015 , the company held long-term credit ratings of bbb ( stable outlook ) and baa2 ( stable outlook ) by s&p and moody 2019s , respectively . contractual obligations for future payments under existing debt and lease commitments and purchase obligations at december 31 , 2015 , were as follows: .
what percentage of contractual obligations for future payments under existing debt and lease commitments and purchase obligations at december 31 , 2015 are due to maturities of long-term debt in 2016?
( a ) total debt includes scheduled principal payments only . ( b ) includes $ 2.1 billion relating to fiber supply agreements entered into at the time of the 2006 transformation plan forestland sales and in conjunction with the 2008 acquisition of weyerhaeuser company 2019s containerboard , packaging and recycling business . ( c ) not included in the above table due to the uncertainty as to the amount and timing of the payment are unrecognized tax benefits of approximately $ 101 million . we consider the undistributed earnings of our foreign subsidiaries as of december 31 , 2015 , to be indefinitely reinvested and , accordingly , no u.s . income taxes have been provided thereon . as of december 31 , 2015 , the amount of cash associated with indefinitely reinvested foreign earnings was approximately $ 600 million . we do not anticipate the need to repatriate funds to the united states to satisfy domestic liquidity needs arising in the ordinary course of business , including liquidity needs associated with our domestic debt service requirements . pension obligations and funding at december 31 , 2015 , the projected benefit obligation for the company 2019s u.s . defined benefit plans determined under u.s . gaap was approximately $ 3.5 billion higher than the fair value of plan assets . approximately $ 3.2 billion of this amount relates to plans that are subject to minimum funding requirements . under current irs funding rules , the calculation of minimum funding requirements differs from the calculation of the present value of plan benefits ( the projected benefit obligation ) for accounting purposes . in december 2008 , the worker , retiree and employer recovery act of 2008 ( wera ) was passed by the u.s . congress which provided for pension funding relief and technical corrections . funding contributions depend on the funding method selected by the company , and the timing of its implementation , as well as on actual demographic data and the targeted funding level . the company continually reassesses the amount and timing of any discretionary contributions and elected to make contributions totaling $ 750 million and $ 353 million for the years ended december 31 , 2015 and 2014 , respectively . at this time , we do not expect to have any required contributions to our plans in 2016 , although the company may elect to make future voluntary contributions . the timing and amount of future contributions , which could be material , will depend on a number of factors , including the actual earnings and changes in values of plan assets and changes in interest rates . international paper has announced a voluntary , limited-time opportunity for former employees who are participants in the retirement plan of international paper company ( the pension plan ) to request early payment of their entire pension plan benefit in the form of a single lump sum payment . eligible participants who wish to receive the lump sum payment must make an election between february 29 and april 29 , 2016 , and payment is scheduled to be made on or before june 30 , 2016 . all payments will be made from the pension plan trust assets . the target population has a total liability of $ 3.0 billion . the amount of the total payments will depend on the participation rate of eligible participants , but is expected to be approximately $ 1.5 billion . based on the expected level of payments , settlement accounting rules will apply in the period in which the payments are made . this will result in a plan remeasurement and the recognition in earnings of a pro-rata portion of unamortized net actuarial loss . ilim holding s.a . shareholder 2019s agreement in october 2007 , in connection with the formation of the ilim holding s.a . joint venture , international paper entered into a shareholder 2019s agreement that includes provisions relating to the reconciliation of disputes among the partners . this agreement was amended on may 7 , 2014 . pursuant to the amended agreement , beginning on january 1 , 2017 , either the company or its partners may commence certain procedures specified under the deadlock provisions . if these or any other deadlock provisions are commenced , the company may in certain situations , choose to purchase its partners 2019 50% ( 50 % ) interest in ilim . any such transaction would be subject to review and approval by russian and other relevant antitrust authorities . any such purchase by international paper would result in the consolidation of ilim 2019s financial position and results of operations in all subsequent periods. .