Yemen's humanitarian situation worsened due to a crippling blockade of rebel-held ports by the Saudi-led coalition.
The expansion of ports will be supported with up to United States dollars 40 million from the Saudi-led coalition.
More than 10,000 people have been killed by coalition airstrikes and by fighting on the ground, Reuters said.
Last week, Saudi Arabia deposited $2bn in Yemen's central bank after the government appealed for help to save the country's currency from collapse and prevent a starvation.
According to the UN Office for Coordination of Humanitarian Affairs (OCHA), almost two million children are out of school, and 1.8 million children under the age of five are acutely malnourished - including 400,000 suffering from severe acute malnutrition and are 10 times more likely to die if they do not receive medical treatment.
Bahraini Information Affairs Minister Ali al-Romaihi denounced recurrent Houthi attacks targeting cities in Saudi Arabia with tens of Iran-made ballistic missiles in a risky escalation aimed to undermine the security of the kingdom, the Gulf and the Arab countries. There were no reports of casualties or damage.
Image Years of conflict has caused what the UN says is the world's worst humanitarian crisis
Maliki said: "This hostile action by the Houthi group backed by Iran proves the continued involvement of the Iranian regime's support to the Houthi armed group with qualitative capabilities in clear and explicit defiance of the violation of United Nations resolution (2216) and resolution (2231) in order to threaten the security of Saudi Arabia and threaten regional and worldwide security".
More than 11.3 million Yemenis "urgently require assistance to survive", United Nations aid agency OCHA said in a statement.
Germany "isn't taking any arms exports decisions right now that aren't in line with the results of the preliminary talks", Steffan Seibert, a spokesperson for Merkel, said in a post on Twitter.
Only in the third financial quarter of 2017, German arms sale to Saudi Arabia accounted for US$550 million. The U.S. supports the coalition with refuelling, logistics and intelligence.
The US, which has provided logistical and intelligence support to the coalition and supplied it with weapons, last month called on Saudi leaders to immediately allow in all humanitarian aid.
Berlin has halted all weapons sales to Riyadh and its allies, in part due to the latter's prosecution of an ongoing war in Yemen that is killing civilians by the thousands.