liquidity and capital resources we currently expect to fund all of our cash requirements which are reasonably foreseeable for 2018 , including scheduled debt repayments , new investments in the business , share repurchases , dividend payments , possible business acquisitions and pension contributions , with cash from operating activities , and as needed , additional short-term and/or long-term borrowings . we continue to expect our operating cash flow to remain strong . as of december 31 , 2017 , we had $ 211 million of cash and cash equivalents on hand , of which $ 151 million was held outside of the as of december 31 , 2016 , we had $ 327 million of cash and cash equivalents on hand , of which $ 184 million was held outside of the u.s . as of december 31 , 2015 , we had $ 26 million of deferred tax liabilities for pre-acquisition foreign earnings associated with the legacy nalco entities and legacy champion entities that we intended to repatriate . these liabilities were recorded as part of the respective purchase price accounting of each transaction . the remaining foreign earnings were repatriated in 2016 , reducing the deferred tax liabilities to zero at december 31 , 2016 . as of december 31 , 2017 we had a $ 2.0 billion multi-year credit facility , which expires in november 2022 . the credit facility has been established with a diverse syndicate of banks . there were no borrowings under our credit facility as of december 31 , 2017 or 2016 . the credit facility supports our $ 2.0 billion u.s . commercial paper program and $ 2.0 billion european commercial paper program . combined borrowing under these two commercial paper programs may not exceed $ 2.0 billion . at year-end , we had no amount outstanding under the european commercial paper program and no amount outstanding under the u.s . commercial paper program . additionally , we have uncommitted credit lines of $ 660 million with major international banks and financial institutions to support our general global funding needs . most of these lines are used to support global cash pooling structures . approximately $ 643 million of these credit lines were available for use as of year-end 2017 . bank supported letters of credit , surety bonds and guarantees total $ 198 million and represent commercial business transactions . we do not have any other significant unconditional purchase obligations or commercial commitments . as of december 31 , 2017 , our short-term borrowing program was rated a-2 by standard & poor 2019s and p-2 by moody 2019s . as of december 31 , 2017 , standard & poor 2019s and moody 2019s rated our long-term credit at a- ( stable outlook ) and baa1 ( stable outlook ) , respectively . a reduction in our credit ratings could limit or preclude our ability to issue commercial paper under our current programs , or could also adversely affect our ability to renew existing , or negotiate new , credit facilities in the future and could increase the cost of these facilities . should this occur , we could seek additional sources of funding , including issuing additional term notes or bonds . in addition , we have the ability , at our option , to draw upon our $ 2.0 billion of committed credit facility . we are in compliance with our debt covenants and other requirements of our credit agreements and indentures . a schedule of our various obligations as of december 31 , 2017 are summarized in the following table: .
what portion of the balance of cash and cash equivalents on hand is held outside u.s . in 2017?
* interest on variable rate debt was calculated using the interest rate at year-end 2017 . during the fourth quarter of 2017 , we recorded a one-time transition tax related to enactment of the tax act . the expense is primarily related to the one-time transition tax , which is payable over eight years . as discussed further in note 12 , this balance is a provisional amount and is subject to adjustment during the measurement period of up to one year following the enactment of the tax act , as provided by recent sec guidance . as of december 31 , 2017 , our gross liability for uncertain tax positions was $ 68 million . we are not able to reasonably estimate the amount by which the liability will increase or decrease over an extended period of time or whether a cash settlement of the liability will be required . therefore , these amounts have been excluded from the schedule of contractual obligations. .