TOKYO  - The yen climbed against the dollar and euro in Asia Monday as fears grow about violent unrest in Iraq and possible gas supply disruptions in Europe tied to the Ukraine crisis.

In Tokyo the dollar bought 101.73 yen compared with 102.04 yen in US trade Friday, while the euro slipped to 137.79 yen from 138.16 yen.

The European single currency was also at $1.3541 from $1.3538.

Investors are nervously tracking events in Iraq as Islamic militants sweep though the country, taking over key cities and moving towards Baghdad as US-trained Iraqi government forces crumble.

There are also fears Europe will be hit by gas supply disruptions after Ukraine failed to broker an 11th-hour deal with Russia in a feud that has stoked the worst East-West crisis since the Cold War.

Ukraine hosted the talks hoping to keep an energy shortage from compounding the new pro-Western leaders' problems as they confront a two-month separatist insurgency threatening the survival of their ex-Soviet state.

The geopolitical jitters pushed traders into the yen, which tends to be bought as a safe-haven currency during times of turmoil and uncertainty.

Investors will be keenly watching a meeting of the Federal Reserve's policy setting committee and fresh economic data, including US industrial production and housing starts, later in the week.

The US central bank is expected to further reduce its monthly asset-buying plan by another $10 billion as the world's number one economy improves.

"The FOMC (Federal Open Market Committee) meeting on Wednesday will undoubtedly be the focus of the week ahead," Credit Agricole said.

The dollar was mixed with other Asia-Pacific units, rising to Sg$1.2504 from Sg$1.2484 on Friday, to 1,019.59 South Korean won from 1,017.88 won and to 43.86 Philippine pesos 43.79 pesos.

It also strengthened to 11,817 Indonesian rupiah from 11,787.50 rupiah and to 59.99 Indian rupees from 59.47 rupees but fell to 32.36 Thai baht from 32.38 baht, while remaining unchanged at Tw$30.00.