No they are not assets. Broadly speaking, there are five financial statement items (or better categories). Assets, liabilities, equity, revenue and expenses.
Asset, Liabilities and equity are balance sheet items while revenue and expenses are income statement items.
The only relevant to the question asset that I can think of is prepaid expenses. They are assets for the company since the company is expected to realize economic benefit and has already transfer economic value to the supplier. Prepaid expenses relate to future economic periods and are not included in the income statement.
Expenses are everything that the company incurs to generate the sales that it generates. In addition, the assets are part of the balance sheet (or the statement of financial position as it’s called). Expenses are part of the income statement (or the statement of comprehensive income as it’s called).