Oil prices rose on Tuesday amid concerns over the supply from Iran and South Sudan, as well as the prospect of the global economic slowdown hitting demand.

Brent crude rose 90 cents to $111.65 a barrel, while US crude jumped $1.11 to a new high of $99.89 a barrel.

Investors are worried about supplies, as the US plans to levy more sanctions on Iran, which is the OPEC’s second largest oil producer.

The rise in price was also influenced by the weakening US dollar after Greece raised hopes that it could reach a debt deal this week.

South Sudan’s decision to keep its production shut added to the supply fears, reports Reuters.