Sri Lanka imposed new taxes on motor vehicles, telecoms, banks and liquor to boost revenue in its 2018 budget presented on Thursday, as the budget deficit for the current year slipped to 5.2 percent of the gross domestic product.

"There was heavy imports ahead of the budget. Some banks also bought dollars to cover their short positions," a currency dealer said asking not to be named.

The spot rupee closed at 153.60/70 per dollar, compared with Wednesday's close of 153.33/40.

Sri Lanka's Finance Minister Mangala Samaraweera had on Wednesday announced tax concessions worth a monthly 1.5 billion rupees ($9.8 million). The presentation of Thursday's budget ended after Sri Lanka's markets closed.

The rupee has slipped 2.6 percent so far this year. The central bank said on Tuesday, after holding the key monetary policy rates steady, that pressure on the exchange rate has reduced due to the flexibility it had allowed.

The island nation has seen 18.1 billion rupees ($117.92 million) worth of net inflows into equities this year as of Wednesday's close, and 42.7 billion rupees into government securities as of Nov. 1, official data showed.