It is true that there are differences in the way US GAAP values assets compared to IFRS. Most notable is the difference in how they handle intangibles, like goodwill or intellectual property. US GAAP capitalizes and amortizes intangibles over their useful lives, while IFRS does not amortize them but must test for impairment every year.
Depending on whether an organisation uses US GAAPs or IFRS, they may use different accounting methods. For example, US GAAPs require the use of historical costs, while IFRS permits companies to use other methods, such as the fair value method or revaluation methods, when valuing specific assets. Last but not least, US GAAP does not allow organizations to restate previous period financial statements. IFRS however allows for restatement if certain conditions are met.