what the treatment of buy assets with foregin currency?

Answer 1

It depends on what your asset is. The initial recording is the same for all assets, but the subsequent treatment depends on whether your asset is a monetary or non-monetary item.

A foreign currency transaction should be recorded initially at the rate of exchange at the date of the transaction. [IAS 21.20-22]

At each subsequent balance sheet date: [IAS 21.23]
(a) foreign currency monetary items (e.g. accounts receivable) shall be translated using the closing rate;
(b) non-monetary items that are measured in terms of historical cost in a foreign currency (e.g. inventories, plant & equipment) shall be translated using the exchange rate at the date of the transaction; and
(c) non-monetary items that are measured at fair value in a foreign currency (e.g. property) shall be translated using the exchange rates at the date when the fair value was determined.

Answer 2

Foreign to you, or to the country where you are buying the assets?